set_theory.ordinal.principalMathlib.SetTheory.Ordinal.Principal

This file has been ported!

Changes since the initial port

The following section lists changes to this file in mathlib3 and mathlib4 that occured after the initial port. Most recent changes are shown first. Hovering over a commit will show all commits associated with the same mathlib3 commit.

Changes in mathlib3

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feat(set_theory/ordinal/natural_ops): define natural multiplication (#14324)
Diff
@@ -85,31 +85,21 @@ nfp_le $ λ n, (ho.iterate_lt hao n).le
 
 /-! ### Principal ordinals are unbounded -/
 
-/-- The least strict upper bound of `op` applied to all pairs of ordinals less than `o`. This is
-essentially a two-argument version of `ordinal.blsub`. -/
-def blsub₂ (op : ordinal → ordinal → ordinal) (o : ordinal) : ordinal :=
-lsub (λ x : o.out.α × o.out.α, op (typein (<) x.1) (typein (<) x.2))
-
-theorem lt_blsub₂ (op : ordinal → ordinal → ordinal) {o : ordinal} {a b : ordinal} (ha : a < o)
-  (hb : b < o) : op a b < blsub₂ op o :=
-begin
-  convert lt_lsub _ (prod.mk (enum (<) a (by rwa type_lt)) (enum (<) b (by rwa type_lt))),
-  simp only [typein_enum]
-end
-
 theorem principal_nfp_blsub₂ (op : ordinal → ordinal → ordinal) (o : ordinal) :
-  principal op (nfp (blsub₂.{u u} op) o) :=
+  principal op (nfp (λ o', blsub₂.{u u u} o' o' (λ a _ b _, op a b)) o) :=
 λ a b ha hb, begin
   rw lt_nfp at *,
   cases ha with m hm,
   cases hb with n hn,
-  cases le_total ((blsub₂.{u u} op)^[m] o) ((blsub₂.{u u} op)^[n] o) with h h,
+  cases le_total
+    ((λ o', blsub₂.{u u u} o' o' (λ a _ b _, op a b))^[m] o)
+    ((λ o', blsub₂.{u u u} o' o' (λ a _ b _, op a b))^[n] o) with h h,
   { use n + 1,
     rw function.iterate_succ',
-    exact lt_blsub₂ op (hm.trans_le h) hn },
+    exact lt_blsub₂ _ (hm.trans_le h) hn },
   { use m + 1,
     rw function.iterate_succ',
-    exact lt_blsub₂ op hm (hn.trans_le h) },
+    exact lt_blsub₂ _ hm (hn.trans_le h) }
 end
 
 theorem unbounded_principal (op : ordinal → ordinal → ordinal) :

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(first ported)

Changes in mathlib3port

mathlib3
mathlib3port
Diff
@@ -157,7 +157,7 @@ theorem principal_add_of_le_one {o : Ordinal} (ho : o ≤ 1) : Principal (· + 
 theorem principal_add_isLimit {o : Ordinal} (ho₁ : 1 < o) (ho : Principal (· + ·) o) : o.IsLimit :=
   by
   refine' ⟨fun ho₀ => _, fun a hao => _⟩
-  · rw [ho₀] at ho₁ 
+  · rw [ho₀] at ho₁
     exact not_lt_of_gt zero_lt_one ho₁
   · cases' eq_or_ne a 0 with ha ha
     · rw [ha, succ_zero]
@@ -176,7 +176,7 @@ theorem principal_add_iff_add_left_eq_self {o : Ordinal} :
     · exact op_eq_self_of_principal hao (add_is_normal a) ho (principal_add_is_limit ho₁ ho)
     · rcases le_one_iff.1 ho₁ with (rfl | rfl)
       · exact (Ordinal.not_lt_zero a hao).elim
-      · rw [lt_one_iff_zero] at hao 
+      · rw [lt_one_iff_zero] at hao
         rw [hao, zero_add]
   · rw [← h a hao]
     exact (add_is_normal a).StrictMono hbo
@@ -187,12 +187,12 @@ theorem principal_add_iff_add_left_eq_self {o : Ordinal} :
 theorem exists_lt_add_of_not_principal_add {a} (ha : ¬Principal (· + ·) a) :
     ∃ (b c : _) (hb : b < a) (hc : c < a), b + c = a :=
   by
-  unfold principal at ha 
-  push_neg at ha 
+  unfold principal at ha
+  push_neg at ha
   rcases ha with ⟨b, c, hb, hc, H⟩
   refine'
     ⟨b, _, hb, lt_of_le_of_ne (sub_le_self a b) fun hab => _, Ordinal.add_sub_cancel_of_le hb.le⟩
-  rw [← sub_le, hab] at H 
+  rw [← sub_le, hab] at H
   exact H.not_lt hc
 #align ordinal.exists_lt_add_of_not_principal_add Ordinal.exists_lt_add_of_not_principal_add
 -/
@@ -229,9 +229,9 @@ theorem add_omega_opow {a b : Ordinal} (h : a < (omega^b)) : a + (omega^b) = (om
   by
   refine' le_antisymm _ (le_add_left _ _)
   revert h; refine' limit_rec_on b (fun h => _) (fun b _ h => _) fun b l IH h => _
-  · rw [opow_zero, ← succ_zero, lt_succ_iff, Ordinal.le_zero] at h 
+  · rw [opow_zero, ← succ_zero, lt_succ_iff, Ordinal.le_zero] at h
     rw [h, zero_add]
-  · rw [opow_succ] at h 
+  · rw [opow_succ] at h
     rcases(lt_mul_of_limit omega_is_limit).1 h with ⟨x, xo, ax⟩
     refine' le_trans (add_le_add_right (le_of_lt ax) _) _
     rw [opow_succ, ← mul_add, add_omega xo]
@@ -265,7 +265,7 @@ theorem principal_add_iff_zero_or_omega_opow {o : Ordinal} :
         fun ⟨b, e⟩ => e.symm ▸ fun a => add_omega_opow⟩
     have := H _ h
     have := lt_opow_succ_log_self one_lt_omega o
-    rw [opow_succ, lt_mul_of_limit omega_is_limit] at this 
+    rw [opow_succ, lt_mul_of_limit omega_is_limit] at this
     rcases this with ⟨a, ao, h'⟩
     rcases lt_omega.1 ao with ⟨n, rfl⟩; clear ao
     revert h'; apply not_lt_of_le
@@ -304,7 +304,7 @@ theorem mul_principal_add_is_principal_add (a : Ordinal.{u}) {b : Ordinal.{u}} (
   · rcases eq_zero_or_pos b with (rfl | hb₁')
     · rw [MulZeroClass.mul_zero]
       exact principal_zero
-    · rw [← succ_le_iff, succ_zero] at hb₁' 
+    · rw [← succ_le_iff, succ_zero] at hb₁'
       intro c d hc hd
       rw [lt_mul_of_limit (principal_add_is_limit (lt_of_le_of_ne hb₁' hb₁.symm) hb)] at *
       · rcases hc with ⟨x, hx, hx'⟩
@@ -340,7 +340,7 @@ theorem principal_mul_of_le_two {o : Ordinal} (ho : o ≤ 2) : Principal (· * 
   by
   rcases lt_or_eq_of_le ho with (ho | rfl)
   · have h₂ : succ (1 : Ordinal) = 2 := rfl
-    rw [← h₂, lt_succ_iff] at ho 
+    rw [← h₂, lt_succ_iff] at ho
     rcases lt_or_eq_of_le ho with (ho | rfl)
     · rw [lt_one_iff_zero.1 ho]
       exact principal_zero
@@ -353,8 +353,8 @@ theorem principal_mul_of_le_two {o : Ordinal} (ho : o ≤ 2) : Principal (· * 
 theorem principal_add_of_principal_mul {o : Ordinal} (ho : Principal (· * ·) o) (ho₂ : o ≠ 2) :
     Principal (· + ·) o := by
   cases' lt_or_gt_of_ne ho₂ with ho₁ ho₂
-  · change o < succ 1 at ho₁ 
-    rw [lt_succ_iff] at ho₁ 
+  · change o < succ 1 at ho₁
+    rw [lt_succ_iff] at ho₁
     exact principal_add_of_le_one ho₁
   · refine' fun a b hao hbo => lt_of_le_of_lt _ (ho (max_lt hao hbo) ho₂)
     rw [mul_two]
@@ -378,11 +378,11 @@ theorem principal_mul_iff_mul_left_eq {o : Ordinal} :
     · convert one_mul o
       apply le_antisymm
       · have : a < succ 1 := hao.trans_le ho
-        rwa [lt_succ_iff] at this 
-      · rwa [← succ_le_iff, succ_zero] at ha₀ 
+        rwa [lt_succ_iff] at this
+      · rwa [← succ_le_iff, succ_zero] at ha₀
     · exact op_eq_self_of_principal hao (mul_is_normal ha₀) h (principal_mul_is_limit ho h)
   · rcases eq_or_ne a 0 with (rfl | ha); · rwa [MulZeroClass.zero_mul]
-    rw [← Ordinal.pos_iff_ne_zero] at ha 
+    rw [← Ordinal.pos_iff_ne_zero] at ha
     rw [← h a ha hao]
     exact (mul_is_normal ha).StrictMono hbo
 #align ordinal.principal_mul_iff_mul_left_eq Ordinal.principal_mul_iff_mul_left_eq
@@ -407,7 +407,7 @@ theorem mul_lt_omega_opow {a b c : Ordinal} (c0 : 0 < c) (ha : a < (omega^c)) (h
   by
   rcases zero_or_succ_or_limit c with (rfl | ⟨c, rfl⟩ | l)
   · exact (lt_irrefl _).elim c0
-  · rw [opow_succ] at ha 
+  · rw [opow_succ] at ha
     rcases((mul_is_normal <| opow_pos _ omega_pos).limit_lt omega_is_limit).1 ha with ⟨n, hn, an⟩
     apply (mul_le_mul_right' (le_of_lt an) _).trans_lt
     rw [opow_succ, mul_assoc, mul_lt_mul_iff_left (opow_pos _ omega_pos)]
@@ -444,7 +444,7 @@ theorem principal_add_of_principal_mul_opow {o b : Ordinal} (hb : 1 < b)
     (ho : Principal (· * ·) (b^o)) : Principal (· + ·) o := fun x y hx hy =>
   by
   have := ho ((opow_lt_opow_iff_right hb).2 hx) ((opow_lt_opow_iff_right hb).2 hy)
-  rwa [← opow_add, opow_lt_opow_iff_right hb] at this 
+  rwa [← opow_add, opow_lt_opow_iff_right hb] at this
 #align ordinal.principal_add_of_principal_mul_opow Ordinal.principal_add_of_principal_mul_opow
 -/
 
@@ -462,7 +462,7 @@ theorem principal_mul_iff_le_two_or_omega_opow_opow {o : Ordinal} :
     rcases principal_add_iff_zero_or_omega_opow.1
         (principal_add_of_principal_mul_opow one_lt_omega ho) with
       (rfl | ⟨b, rfl⟩)
-    · rw [opow_zero] at ho₂ 
+    · rw [opow_zero] at ho₂
       exact ((lt_succ 1).not_le ho₂.le).elim
     exact Or.inr ⟨b, rfl⟩
   · rintro (ho₂ | ⟨a, rfl⟩)
Diff
@@ -202,7 +202,7 @@ theorem principal_add_iff_add_lt_ne_self {a} :
     Principal (· + ·) a ↔ ∀ ⦃b c⦄, b < a → c < a → b + c ≠ a :=
   ⟨fun ha b c hb hc => (ha hb hc).Ne, fun H =>
     by
-    by_contra' ha
+    by_contra! ha
     rcases exists_lt_add_of_not_principal_add ha with ⟨b, c, hb, hc, rfl⟩
     exact (H hb hc).irrefl⟩
 #align ordinal.principal_add_iff_add_lt_ne_self Ordinal.principal_add_iff_add_lt_ne_self
Diff
@@ -3,7 +3,7 @@ Copyright (c) 2022 Violeta Hernández Palacios. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Violeta Hernández Palacios
 -/
-import Mathbin.SetTheory.Ordinal.FixedPoint
+import SetTheory.Ordinal.FixedPoint
 
 #align_import set_theory.ordinal.principal from "leanprover-community/mathlib"@"31b269b60935483943542d547a6dd83a66b37dc7"
 
Diff
@@ -2,14 +2,11 @@
 Copyright (c) 2022 Violeta Hernández Palacios. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Violeta Hernández Palacios
-
-! This file was ported from Lean 3 source module set_theory.ordinal.principal
-! leanprover-community/mathlib commit 31b269b60935483943542d547a6dd83a66b37dc7
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathbin.SetTheory.Ordinal.FixedPoint
 
+#align_import set_theory.ordinal.principal from "leanprover-community/mathlib"@"31b269b60935483943542d547a6dd83a66b37dc7"
+
 /-!
 ### Principal ordinals
 
Diff
@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Violeta Hernández Palacios
 
 ! This file was ported from Lean 3 source module set_theory.ordinal.principal
-! leanprover-community/mathlib commit 3dadefa3f544b1db6214777fe47910739b54c66a
+! leanprover-community/mathlib commit 31b269b60935483943542d547a6dd83a66b37dc7
 ! Please do not edit these lines, except to modify the commit id
 ! if you have ported upstream changes.
 -/
@@ -111,38 +111,23 @@ theorem nfp_le_of_principal {op : Ordinal → Ordinal → Ordinal} {a o : Ordina
 /-! ### Principal ordinals are unbounded -/
 
 
-#print Ordinal.blsub₂ /-
-/-- The least strict upper bound of `op` applied to all pairs of ordinals less than `o`. This is
-essentially a two-argument version of `ordinal.blsub`. -/
-def blsub₂ (op : Ordinal → Ordinal → Ordinal) (o : Ordinal) : Ordinal :=
-  lsub fun x : o.out.α × o.out.α => op (typein (· < ·) x.1) (typein (· < ·) x.2)
-#align ordinal.blsub₂ Ordinal.blsub₂
--/
-
-#print Ordinal.lt_blsub₂ /-
-theorem lt_blsub₂ (op : Ordinal → Ordinal → Ordinal) {o : Ordinal} {a b : Ordinal} (ha : a < o)
-    (hb : b < o) : op a b < blsub₂ op o :=
-  by
-  convert
-    lt_lsub _ (Prod.mk (enum (· < ·) a (by rwa [type_lt])) (enum (· < ·) b (by rwa [type_lt])))
-  simp only [typein_enum]
-#align ordinal.lt_blsub₂ Ordinal.lt_blsub₂
--/
-
 #print Ordinal.principal_nfp_blsub₂ /-
 theorem principal_nfp_blsub₂ (op : Ordinal → Ordinal → Ordinal) (o : Ordinal) :
-    Principal op (nfp (blsub₂.{u, u} op) o) := fun a b ha hb =>
-  by
+    Principal op (nfp (fun o' => blsub₂.{u, u, u} o' o' fun a _ b _ => op a b) o) :=
+  fun a b ha hb => by
   rw [lt_nfp] at *
   cases' ha with m hm
   cases' hb with n hn
-  cases' le_total ((blsub₂.{u, u} op^[m]) o) ((blsub₂.{u, u} op^[n]) o) with h h
+  cases'
+    le_total (((fun o' => blsub₂.{u, u, u} o' o' fun a _ b _ => op a b)^[m]) o)
+      (((fun o' => blsub₂.{u, u, u} o' o' fun a _ b _ => op a b)^[n]) o) with
+    h h
   · use n + 1
     rw [Function.iterate_succ']
-    exact lt_blsub₂ op (hm.trans_le h) hn
+    exact lt_blsub₂ _ (hm.trans_le h) hn
   · use m + 1
     rw [Function.iterate_succ']
-    exact lt_blsub₂ op hm (hn.trans_le h)
+    exact lt_blsub₂ _ hm (hn.trans_le h)
 #align ordinal.principal_nfp_blsub₂ Ordinal.principal_nfp_blsub₂
 -/
 
Diff
@@ -41,7 +41,6 @@ open Order
 
 namespace Ordinal
 
--- mathport name: ordinal.pow
 local infixr:0 "^" => @pow Ordinal Ordinal Ordinal.hasPow
 
 /-! ### Principal ordinals -/
@@ -71,6 +70,7 @@ theorem principal_zero {op : Ordinal → Ordinal → Ordinal} : Principal op 0 :
 #align ordinal.principal_zero Ordinal.principal_zero
 -/
 
+#print Ordinal.principal_one_iff /-
 @[simp]
 theorem principal_one_iff {op : Ordinal → Ordinal → Ordinal} : Principal op 1 ↔ op 0 0 = 0 :=
   by
@@ -79,6 +79,7 @@ theorem principal_one_iff {op : Ordinal → Ordinal → Ordinal} : Principal op
     exact h zero_lt_one zero_lt_one
   · rwa [lt_one_iff_zero, ha, hb] at *
 #align ordinal.principal_one_iff Ordinal.principal_one_iff
+-/
 
 #print Ordinal.Principal.iterate_lt /-
 theorem Principal.iterate_lt {op : Ordinal → Ordinal → Ordinal} {a o : Ordinal} (hao : a < o)
@@ -155,17 +156,22 @@ theorem unbounded_principal (op : Ordinal → Ordinal → Ordinal) :
 /-! #### Additive principal ordinals -/
 
 
+#print Ordinal.principal_add_one /-
 theorem principal_add_one : Principal (· + ·) 1 :=
   principal_one_iff.2 <| zero_add 0
 #align ordinal.principal_add_one Ordinal.principal_add_one
+-/
 
+#print Ordinal.principal_add_of_le_one /-
 theorem principal_add_of_le_one {o : Ordinal} (ho : o ≤ 1) : Principal (· + ·) o :=
   by
   rcases le_one_iff.1 ho with (rfl | rfl)
   · exact principal_zero
   · exact principal_add_one
 #align ordinal.principal_add_of_le_one Ordinal.principal_add_of_le_one
+-/
 
+#print Ordinal.principal_add_isLimit /-
 theorem principal_add_isLimit {o : Ordinal} (ho₁ : 1 < o) (ho : Principal (· + ·) o) : o.IsLimit :=
   by
   refine' ⟨fun ho₀ => _, fun a hao => _⟩
@@ -177,6 +183,7 @@ theorem principal_add_isLimit {o : Ordinal} (ho₁ : 1 < o) (ho : Principal (·
     · refine' lt_of_le_of_lt _ (ho hao hao)
       rwa [← add_one_eq_succ, add_le_add_iff_left, one_le_iff_ne_zero]
 #align ordinal.principal_add_is_limit Ordinal.principal_add_isLimit
+-/
 
 #print Ordinal.principal_add_iff_add_left_eq_self /-
 theorem principal_add_iff_add_left_eq_self {o : Ordinal} :
@@ -235,6 +242,7 @@ theorem principal_add_omega : Principal (· + ·) omega :=
 #align ordinal.principal_add_omega Ordinal.principal_add_omega
 -/
 
+#print Ordinal.add_omega_opow /-
 theorem add_omega_opow {a b : Ordinal} (h : a < (omega^b)) : a + (omega^b) = (omega^b) :=
   by
   refine' le_antisymm _ (le_add_left _ _)
@@ -253,11 +261,15 @@ theorem add_omega_opow {a b : Ordinal} (h : a < (omega^b)) : a + (omega^b) = (om
             (IH _ (max_lt xb yb) (ax.trans_le <| opow_le_opow_right omega_pos (le_max_left _ _)))
             (opow_le_opow_right omega_pos <| le_of_lt <| max_lt xb yb))
 #align ordinal.add_omega_opow Ordinal.add_omega_opow
+-/
 
+#print Ordinal.principal_add_omega_opow /-
 theorem principal_add_omega_opow (o : Ordinal) : Principal (· + ·) (omega^o) :=
   principal_add_iff_add_left_eq_self.2 fun a => add_omega_opow
 #align ordinal.principal_add_omega_opow Ordinal.principal_add_omega_opow
+-/
 
+#print Ordinal.principal_add_iff_zero_or_omega_opow /-
 /-- The main characterization theorem for additive principal ordinals. -/
 theorem principal_add_iff_zero_or_omega_opow {o : Ordinal} :
     Principal (· + ·) o ↔ o = 0 ∨ ∃ a, o = (omega^a) :=
@@ -280,7 +292,9 @@ theorem principal_add_iff_zero_or_omega_opow {o : Ordinal} :
     induction' n with n IH; · simp only [Nat.cast_zero, MulZeroClass.mul_zero, zero_add]
     simp only [Nat.cast_succ, mul_add_one, add_assoc, this, IH]
 #align ordinal.principal_add_iff_zero_or_omega_opow Ordinal.principal_add_iff_zero_or_omega_opow
+-/
 
+#print Ordinal.opow_principal_add_of_principal_add /-
 theorem opow_principal_add_of_principal_add {a} (ha : Principal (· + ·) a) (b : Ordinal) :
     Principal (· + ·) (a^b) :=
   by
@@ -290,11 +304,15 @@ theorem opow_principal_add_of_principal_add {a} (ha : Principal (· + ·) a) (b
     · rwa [zero_opow hb]
   · rw [← opow_mul]; exact principal_add_omega_opow _
 #align ordinal.opow_principal_add_of_principal_add Ordinal.opow_principal_add_of_principal_add
+-/
 
+#print Ordinal.add_absorp /-
 theorem add_absorp {a b c : Ordinal} (h₁ : a < (omega^b)) (h₂ : (omega^b) ≤ c) : a + c = c := by
   rw [← Ordinal.add_sub_cancel_of_le h₂, ← add_assoc, add_omega_opow h₁]
 #align ordinal.add_absorp Ordinal.add_absorp
+-/
 
+#print Ordinal.mul_principal_add_is_principal_add /-
 theorem mul_principal_add_is_principal_add (a : Ordinal.{u}) {b : Ordinal.{u}} (hb₁ : b ≠ 1)
     (hb : Principal (· + ·) b) : Principal (· + ·) (a * b) :=
   by
@@ -314,14 +332,18 @@ theorem mul_principal_add_is_principal_add (a : Ordinal.{u}) {b : Ordinal.{u}} (
         exact Left.add_lt_add hx' hy'
       assumption'
 #align ordinal.mul_principal_add_is_principal_add Ordinal.mul_principal_add_is_principal_add
+-/
 
 /-! #### Multiplicative principal ordinals -/
 
 
+#print Ordinal.principal_mul_one /-
 theorem principal_mul_one : Principal (· * ·) 1 := by rw [principal_one_iff];
   exact MulZeroClass.zero_mul _
 #align ordinal.principal_mul_one Ordinal.principal_mul_one
+-/
 
+#print Ordinal.principal_mul_two /-
 theorem principal_mul_two : Principal (· * ·) 2 := fun a b ha hb =>
   by
   have h₂ : succ (1 : Ordinal) = 2 := rfl
@@ -329,7 +351,9 @@ theorem principal_mul_two : Principal (· * ·) 2 := fun a b ha hb =>
   convert mul_le_mul' ha hb
   exact (mul_one 1).symm
 #align ordinal.principal_mul_two Ordinal.principal_mul_two
+-/
 
+#print Ordinal.principal_mul_of_le_two /-
 theorem principal_mul_of_le_two {o : Ordinal} (ho : o ≤ 2) : Principal (· * ·) o :=
   by
   rcases lt_or_eq_of_le ho with (ho | rfl)
@@ -341,7 +365,9 @@ theorem principal_mul_of_le_two {o : Ordinal} (ho : o ≤ 2) : Principal (· * 
     · exact principal_mul_one
   · exact principal_mul_two
 #align ordinal.principal_mul_of_le_two Ordinal.principal_mul_of_le_two
+-/
 
+#print Ordinal.principal_add_of_principal_mul /-
 theorem principal_add_of_principal_mul {o : Ordinal} (ho : Principal (· * ·) o) (ho₂ : o ≠ 2) :
     Principal (· + ·) o := by
   cases' lt_or_gt_of_ne ho₂ with ho₁ ho₂
@@ -352,12 +378,16 @@ theorem principal_add_of_principal_mul {o : Ordinal} (ho : Principal (· * ·) o
     rw [mul_two]
     exact add_le_add (le_max_left a b) (le_max_right a b)
 #align ordinal.principal_add_of_principal_mul Ordinal.principal_add_of_principal_mul
+-/
 
+#print Ordinal.principal_mul_isLimit /-
 theorem principal_mul_isLimit {o : Ordinal.{u}} (ho₂ : 2 < o) (ho : Principal (· * ·) o) :
     o.IsLimit :=
   principal_add_isLimit ((lt_succ 1).trans ho₂) (principal_add_of_principal_mul ho (ne_of_gt ho₂))
 #align ordinal.principal_mul_is_limit Ordinal.principal_mul_isLimit
+-/
 
+#print Ordinal.principal_mul_iff_mul_left_eq /-
 theorem principal_mul_iff_mul_left_eq {o : Ordinal} :
     Principal (· * ·) o ↔ ∀ a, 0 < a → a < o → a * o = o :=
   by
@@ -374,16 +404,22 @@ theorem principal_mul_iff_mul_left_eq {o : Ordinal} :
     rw [← h a ha hao]
     exact (mul_is_normal ha).StrictMono hbo
 #align ordinal.principal_mul_iff_mul_left_eq Ordinal.principal_mul_iff_mul_left_eq
+-/
 
+#print Ordinal.principal_mul_omega /-
 theorem principal_mul_omega : Principal (· * ·) omega := fun a b ha hb =>
   match a, b, lt_omega.1 ha, lt_omega.1 hb with
   | _, _, ⟨m, rfl⟩, ⟨n, rfl⟩ => by rw [← nat_cast_mul]; apply nat_lt_omega
 #align ordinal.principal_mul_omega Ordinal.principal_mul_omega
+-/
 
+#print Ordinal.mul_omega /-
 theorem mul_omega {a : Ordinal} (a0 : 0 < a) (ha : a < omega) : a * omega = omega :=
   principal_mul_iff_mul_left_eq.1 principal_mul_omega a a0 ha
 #align ordinal.mul_omega Ordinal.mul_omega
+-/
 
+#print Ordinal.mul_lt_omega_opow /-
 theorem mul_lt_omega_opow {a b c : Ordinal} (c0 : 0 < c) (ha : a < (omega^c)) (hb : b < omega) :
     a * b < (omega^c) :=
   by
@@ -399,7 +435,9 @@ theorem mul_lt_omega_opow {a b c : Ordinal} (c0 : 0 < c) (ha : a < (omega^c)) (h
     rw [← opow_succ, opow_lt_opow_iff_right one_lt_omega]
     exact l.2 _ hx
 #align ordinal.mul_lt_omega_opow Ordinal.mul_lt_omega_opow
+-/
 
+#print Ordinal.mul_omega_opow_opow /-
 theorem mul_omega_opow_opow {a b : Ordinal} (a0 : 0 < a) (h : a < (omega^omega^b)) :
     a * (omega^omega^b) = (omega^omega^b) :=
   by
@@ -411,18 +449,24 @@ theorem mul_omega_opow_opow {a b : Ordinal} (a0 : 0 < a) (h : a < (omega^omega^b
   apply (mul_le_mul_right' (le_of_lt ax) _).trans
   rw [← opow_add, add_omega_opow xb]
 #align ordinal.mul_omega_opow_opow Ordinal.mul_omega_opow_opow
+-/
 
+#print Ordinal.principal_mul_omega_opow_opow /-
 theorem principal_mul_omega_opow_opow (o : Ordinal) : Principal (· * ·) (omega^omega^o) :=
   principal_mul_iff_mul_left_eq.2 fun a => mul_omega_opow_opow
 #align ordinal.principal_mul_omega_opow_opow Ordinal.principal_mul_omega_opow_opow
+-/
 
+#print Ordinal.principal_add_of_principal_mul_opow /-
 theorem principal_add_of_principal_mul_opow {o b : Ordinal} (hb : 1 < b)
     (ho : Principal (· * ·) (b^o)) : Principal (· + ·) o := fun x y hx hy =>
   by
   have := ho ((opow_lt_opow_iff_right hb).2 hx) ((opow_lt_opow_iff_right hb).2 hy)
   rwa [← opow_add, opow_lt_opow_iff_right hb] at this 
 #align ordinal.principal_add_of_principal_mul_opow Ordinal.principal_add_of_principal_mul_opow
+-/
 
+#print Ordinal.principal_mul_iff_le_two_or_omega_opow_opow /-
 /-- The main characterization theorem for multiplicative principal ordinals. -/
 theorem principal_mul_iff_le_two_or_omega_opow_opow {o : Ordinal} :
     Principal (· * ·) o ↔ o ≤ 2 ∨ ∃ a, o = (omega^omega^a) :=
@@ -443,11 +487,15 @@ theorem principal_mul_iff_le_two_or_omega_opow_opow {o : Ordinal} :
     · exact principal_mul_of_le_two ho₂
     · exact principal_mul_omega_opow_opow a
 #align ordinal.principal_mul_iff_le_two_or_omega_opow_opow Ordinal.principal_mul_iff_le_two_or_omega_opow_opow
+-/
 
+#print Ordinal.mul_omega_dvd /-
 theorem mul_omega_dvd {a : Ordinal} (a0 : 0 < a) (ha : a < omega) : ∀ {b}, omega ∣ b → a * b = b
   | _, ⟨b, rfl⟩ => by rw [← mul_assoc, mul_omega a0 ha]
 #align ordinal.mul_omega_dvd Ordinal.mul_omega_dvd
+-/
 
+#print Ordinal.mul_eq_opow_log_succ /-
 theorem mul_eq_opow_log_succ {a b : Ordinal.{u}} (ha : a ≠ 0) (hb : Principal (· * ·) b)
     (hb₂ : 2 < b) : a * b = (b^succ (log b a)) :=
   by
@@ -465,21 +513,26 @@ theorem mul_eq_opow_log_succ {a b : Ordinal.{u}} (ha : a ≠ 0) (hb : Principal
   · rw [opow_succ]
     exact mul_le_mul_right' (opow_log_le_self b ha) b
 #align ordinal.mul_eq_opow_log_succ Ordinal.mul_eq_opow_log_succ
+-/
 
 /-! #### Exponential principal ordinals -/
 
 
+#print Ordinal.principal_opow_omega /-
 theorem principal_opow_omega : Principal (·^·) omega := fun a b ha hb =>
   match a, b, lt_omega.1 ha, lt_omega.1 hb with
   | _, _, ⟨m, rfl⟩, ⟨n, rfl⟩ => by simp_rw [← nat_cast_opow]; apply nat_lt_omega
 #align ordinal.principal_opow_omega Ordinal.principal_opow_omega
+-/
 
+#print Ordinal.opow_omega /-
 theorem opow_omega {a : Ordinal} (a1 : 1 < a) (h : a < omega) : (a^omega) = omega :=
   le_antisymm
     ((opow_le_of_limit (one_le_iff_ne_zero.1 <| le_of_lt a1) omega_isLimit).2 fun b hb =>
       (principal_opow_omega h hb).le)
     (right_le_opow _ a1)
 #align ordinal.opow_omega Ordinal.opow_omega
+-/
 
 end Ordinal
 
Diff
@@ -122,8 +122,8 @@ def blsub₂ (op : Ordinal → Ordinal → Ordinal) (o : Ordinal) : Ordinal :=
 theorem lt_blsub₂ (op : Ordinal → Ordinal → Ordinal) {o : Ordinal} {a b : Ordinal} (ha : a < o)
     (hb : b < o) : op a b < blsub₂ op o :=
   by
-  convert lt_lsub _
-      (Prod.mk (enum (· < ·) a (by rwa [type_lt])) (enum (· < ·) b (by rwa [type_lt])))
+  convert
+    lt_lsub _ (Prod.mk (enum (· < ·) a (by rwa [type_lt])) (enum (· < ·) b (by rwa [type_lt])))
   simp only [typein_enum]
 #align ordinal.lt_blsub₂ Ordinal.lt_blsub₂
 -/
@@ -147,7 +147,7 @@ theorem principal_nfp_blsub₂ (op : Ordinal → Ordinal → Ordinal) (o : Ordin
 
 #print Ordinal.unbounded_principal /-
 theorem unbounded_principal (op : Ordinal → Ordinal → Ordinal) :
-    Set.Unbounded (· < ·) { o | Principal op o } := fun o =>
+    Set.Unbounded (· < ·) {o | Principal op o} := fun o =>
   ⟨_, principal_nfp_blsub₂ op o, (le_nfp _ o).not_lt⟩
 #align ordinal.unbounded_principal Ordinal.unbounded_principal
 -/
@@ -199,7 +199,7 @@ theorem exists_lt_add_of_not_principal_add {a} (ha : ¬Principal (· + ·) a) :
     ∃ (b c : _) (hb : b < a) (hc : c < a), b + c = a :=
   by
   unfold principal at ha 
-  push_neg  at ha 
+  push_neg at ha 
   rcases ha with ⟨b, c, hb, hc, H⟩
   refine'
     ⟨b, _, hb, lt_of_le_of_ne (sub_le_self a b) fun hab => _, Ordinal.add_sub_cancel_of_le hb.le⟩
Diff
@@ -169,7 +169,7 @@ theorem principal_add_of_le_one {o : Ordinal} (ho : o ≤ 1) : Principal (· + 
 theorem principal_add_isLimit {o : Ordinal} (ho₁ : 1 < o) (ho : Principal (· + ·) o) : o.IsLimit :=
   by
   refine' ⟨fun ho₀ => _, fun a hao => _⟩
-  · rw [ho₀] at ho₁
+  · rw [ho₀] at ho₁ 
     exact not_lt_of_gt zero_lt_one ho₁
   · cases' eq_or_ne a 0 with ha ha
     · rw [ha, succ_zero]
@@ -187,7 +187,7 @@ theorem principal_add_iff_add_left_eq_self {o : Ordinal} :
     · exact op_eq_self_of_principal hao (add_is_normal a) ho (principal_add_is_limit ho₁ ho)
     · rcases le_one_iff.1 ho₁ with (rfl | rfl)
       · exact (Ordinal.not_lt_zero a hao).elim
-      · rw [lt_one_iff_zero] at hao
+      · rw [lt_one_iff_zero] at hao 
         rw [hao, zero_add]
   · rw [← h a hao]
     exact (add_is_normal a).StrictMono hbo
@@ -196,14 +196,14 @@ theorem principal_add_iff_add_left_eq_self {o : Ordinal} :
 
 #print Ordinal.exists_lt_add_of_not_principal_add /-
 theorem exists_lt_add_of_not_principal_add {a} (ha : ¬Principal (· + ·) a) :
-    ∃ (b c : _)(hb : b < a)(hc : c < a), b + c = a :=
+    ∃ (b c : _) (hb : b < a) (hc : c < a), b + c = a :=
   by
-  unfold principal at ha
-  push_neg  at ha
+  unfold principal at ha 
+  push_neg  at ha 
   rcases ha with ⟨b, c, hb, hc, H⟩
   refine'
     ⟨b, _, hb, lt_of_le_of_ne (sub_le_self a b) fun hab => _, Ordinal.add_sub_cancel_of_le hb.le⟩
-  rw [← sub_le, hab] at H
+  rw [← sub_le, hab] at H 
   exact H.not_lt hc
 #align ordinal.exists_lt_add_of_not_principal_add Ordinal.exists_lt_add_of_not_principal_add
 -/
@@ -239,9 +239,9 @@ theorem add_omega_opow {a b : Ordinal} (h : a < (omega^b)) : a + (omega^b) = (om
   by
   refine' le_antisymm _ (le_add_left _ _)
   revert h; refine' limit_rec_on b (fun h => _) (fun b _ h => _) fun b l IH h => _
-  · rw [opow_zero, ← succ_zero, lt_succ_iff, Ordinal.le_zero] at h
+  · rw [opow_zero, ← succ_zero, lt_succ_iff, Ordinal.le_zero] at h 
     rw [h, zero_add]
-  · rw [opow_succ] at h
+  · rw [opow_succ] at h 
     rcases(lt_mul_of_limit omega_is_limit).1 h with ⟨x, xo, ax⟩
     refine' le_trans (add_le_add_right (le_of_lt ax) _) _
     rw [opow_succ, ← mul_add, add_omega xo]
@@ -271,7 +271,7 @@ theorem principal_add_iff_zero_or_omega_opow {o : Ordinal} :
         fun ⟨b, e⟩ => e.symm ▸ fun a => add_omega_opow⟩
     have := H _ h
     have := lt_opow_succ_log_self one_lt_omega o
-    rw [opow_succ, lt_mul_of_limit omega_is_limit] at this
+    rw [opow_succ, lt_mul_of_limit omega_is_limit] at this 
     rcases this with ⟨a, ao, h'⟩
     rcases lt_omega.1 ao with ⟨n, rfl⟩; clear ao
     revert h'; apply not_lt_of_le
@@ -304,7 +304,7 @@ theorem mul_principal_add_is_principal_add (a : Ordinal.{u}) {b : Ordinal.{u}} (
   · rcases eq_zero_or_pos b with (rfl | hb₁')
     · rw [MulZeroClass.mul_zero]
       exact principal_zero
-    · rw [← succ_le_iff, succ_zero] at hb₁'
+    · rw [← succ_le_iff, succ_zero] at hb₁' 
       intro c d hc hd
       rw [lt_mul_of_limit (principal_add_is_limit (lt_of_le_of_ne hb₁' hb₁.symm) hb)] at *
       · rcases hc with ⟨x, hx, hx'⟩
@@ -334,7 +334,7 @@ theorem principal_mul_of_le_two {o : Ordinal} (ho : o ≤ 2) : Principal (· * 
   by
   rcases lt_or_eq_of_le ho with (ho | rfl)
   · have h₂ : succ (1 : Ordinal) = 2 := rfl
-    rw [← h₂, lt_succ_iff] at ho
+    rw [← h₂, lt_succ_iff] at ho 
     rcases lt_or_eq_of_le ho with (ho | rfl)
     · rw [lt_one_iff_zero.1 ho]
       exact principal_zero
@@ -345,8 +345,8 @@ theorem principal_mul_of_le_two {o : Ordinal} (ho : o ≤ 2) : Principal (· * 
 theorem principal_add_of_principal_mul {o : Ordinal} (ho : Principal (· * ·) o) (ho₂ : o ≠ 2) :
     Principal (· + ·) o := by
   cases' lt_or_gt_of_ne ho₂ with ho₁ ho₂
-  · change o < succ 1 at ho₁
-    rw [lt_succ_iff] at ho₁
+  · change o < succ 1 at ho₁ 
+    rw [lt_succ_iff] at ho₁ 
     exact principal_add_of_le_one ho₁
   · refine' fun a b hao hbo => lt_of_le_of_lt _ (ho (max_lt hao hbo) ho₂)
     rw [mul_two]
@@ -366,11 +366,11 @@ theorem principal_mul_iff_mul_left_eq {o : Ordinal} :
     · convert one_mul o
       apply le_antisymm
       · have : a < succ 1 := hao.trans_le ho
-        rwa [lt_succ_iff] at this
-      · rwa [← succ_le_iff, succ_zero] at ha₀
+        rwa [lt_succ_iff] at this 
+      · rwa [← succ_le_iff, succ_zero] at ha₀ 
     · exact op_eq_self_of_principal hao (mul_is_normal ha₀) h (principal_mul_is_limit ho h)
   · rcases eq_or_ne a 0 with (rfl | ha); · rwa [MulZeroClass.zero_mul]
-    rw [← Ordinal.pos_iff_ne_zero] at ha
+    rw [← Ordinal.pos_iff_ne_zero] at ha 
     rw [← h a ha hao]
     exact (mul_is_normal ha).StrictMono hbo
 #align ordinal.principal_mul_iff_mul_left_eq Ordinal.principal_mul_iff_mul_left_eq
@@ -389,7 +389,7 @@ theorem mul_lt_omega_opow {a b c : Ordinal} (c0 : 0 < c) (ha : a < (omega^c)) (h
   by
   rcases zero_or_succ_or_limit c with (rfl | ⟨c, rfl⟩ | l)
   · exact (lt_irrefl _).elim c0
-  · rw [opow_succ] at ha
+  · rw [opow_succ] at ha 
     rcases((mul_is_normal <| opow_pos _ omega_pos).limit_lt omega_is_limit).1 ha with ⟨n, hn, an⟩
     apply (mul_le_mul_right' (le_of_lt an) _).trans_lt
     rw [opow_succ, mul_assoc, mul_lt_mul_iff_left (opow_pos _ omega_pos)]
@@ -403,7 +403,7 @@ theorem mul_lt_omega_opow {a b c : Ordinal} (c0 : 0 < c) (ha : a < (omega^c)) (h
 theorem mul_omega_opow_opow {a b : Ordinal} (a0 : 0 < a) (h : a < (omega^omega^b)) :
     a * (omega^omega^b) = (omega^omega^b) :=
   by
-  by_cases b0 : b = 0; · rw [b0, opow_zero, opow_one] at h⊢; exact mul_omega a0 h
+  by_cases b0 : b = 0; · rw [b0, opow_zero, opow_one] at h ⊢; exact mul_omega a0 h
   refine'
     le_antisymm _
       (by simpa only [one_mul] using mul_le_mul_right' (one_le_iff_pos.2 a0) (omega^omega^b))
@@ -420,7 +420,7 @@ theorem principal_add_of_principal_mul_opow {o b : Ordinal} (hb : 1 < b)
     (ho : Principal (· * ·) (b^o)) : Principal (· + ·) o := fun x y hx hy =>
   by
   have := ho ((opow_lt_opow_iff_right hb).2 hx) ((opow_lt_opow_iff_right hb).2 hy)
-  rwa [← opow_add, opow_lt_opow_iff_right hb] at this
+  rwa [← opow_add, opow_lt_opow_iff_right hb] at this 
 #align ordinal.principal_add_of_principal_mul_opow Ordinal.principal_add_of_principal_mul_opow
 
 /-- The main characterization theorem for multiplicative principal ordinals. -/
@@ -436,7 +436,7 @@ theorem principal_mul_iff_le_two_or_omega_opow_opow {o : Ordinal} :
     rcases principal_add_iff_zero_or_omega_opow.1
         (principal_add_of_principal_mul_opow one_lt_omega ho) with
       (rfl | ⟨b, rfl⟩)
-    · rw [opow_zero] at ho₂
+    · rw [opow_zero] at ho₂ 
       exact ((lt_succ 1).not_le ho₂.le).elim
     exact Or.inr ⟨b, rfl⟩
   · rintro (ho₂ | ⟨a, rfl⟩)
Diff
@@ -80,6 +80,7 @@ theorem principal_one_iff {op : Ordinal → Ordinal → Ordinal} : Principal op
   · rwa [lt_one_iff_zero, ha, hb] at *
 #align ordinal.principal_one_iff Ordinal.principal_one_iff
 
+#print Ordinal.Principal.iterate_lt /-
 theorem Principal.iterate_lt {op : Ordinal → Ordinal → Ordinal} {a o : Ordinal} (hao : a < o)
     (ho : Principal op o) (n : ℕ) : (op a^[n]) a < o :=
   by
@@ -87,7 +88,9 @@ theorem Principal.iterate_lt {op : Ordinal → Ordinal → Ordinal} {a o : Ordin
   · rwa [Function.iterate_zero]
   · rw [Function.iterate_succ']; exact ho hao hn
 #align ordinal.principal.iterate_lt Ordinal.Principal.iterate_lt
+-/
 
+#print Ordinal.op_eq_self_of_principal /-
 theorem op_eq_self_of_principal {op : Ordinal → Ordinal → Ordinal} {a o : Ordinal.{u}} (hao : a < o)
     (H : IsNormal (op a)) (ho : Principal op o) (ho' : IsLimit o) : op a o = o :=
   by
@@ -95,11 +98,14 @@ theorem op_eq_self_of_principal {op : Ordinal → Ordinal → Ordinal} {a o : Or
   rw [← IsNormal.bsup_eq.{u, u} H ho', bsup_le_iff]
   exact fun b hbo => (ho hao hbo).le
 #align ordinal.op_eq_self_of_principal Ordinal.op_eq_self_of_principal
+-/
 
+#print Ordinal.nfp_le_of_principal /-
 theorem nfp_le_of_principal {op : Ordinal → Ordinal → Ordinal} {a o : Ordinal} (hao : a < o)
     (ho : Principal op o) : nfp (op a) a ≤ o :=
   nfp_le fun n => (ho.iterate_lt hao n).le
 #align ordinal.nfp_le_of_principal Ordinal.nfp_le_of_principal
+-/
 
 /-! ### Principal ordinals are unbounded -/
 
@@ -112,6 +118,7 @@ def blsub₂ (op : Ordinal → Ordinal → Ordinal) (o : Ordinal) : Ordinal :=
 #align ordinal.blsub₂ Ordinal.blsub₂
 -/
 
+#print Ordinal.lt_blsub₂ /-
 theorem lt_blsub₂ (op : Ordinal → Ordinal → Ordinal) {o : Ordinal} {a b : Ordinal} (ha : a < o)
     (hb : b < o) : op a b < blsub₂ op o :=
   by
@@ -119,6 +126,7 @@ theorem lt_blsub₂ (op : Ordinal → Ordinal → Ordinal) {o : Ordinal} {a b :
       (Prod.mk (enum (· < ·) a (by rwa [type_lt])) (enum (· < ·) b (by rwa [type_lt])))
   simp only [typein_enum]
 #align ordinal.lt_blsub₂ Ordinal.lt_blsub₂
+-/
 
 #print Ordinal.principal_nfp_blsub₂ /-
 theorem principal_nfp_blsub₂ (op : Ordinal → Ordinal → Ordinal) (o : Ordinal) :
@@ -137,10 +145,12 @@ theorem principal_nfp_blsub₂ (op : Ordinal → Ordinal → Ordinal) (o : Ordin
 #align ordinal.principal_nfp_blsub₂ Ordinal.principal_nfp_blsub₂
 -/
 
+#print Ordinal.unbounded_principal /-
 theorem unbounded_principal (op : Ordinal → Ordinal → Ordinal) :
     Set.Unbounded (· < ·) { o | Principal op o } := fun o =>
   ⟨_, principal_nfp_blsub₂ op o, (le_nfp _ o).not_lt⟩
 #align ordinal.unbounded_principal Ordinal.unbounded_principal
+-/
 
 /-! #### Additive principal ordinals -/
 
@@ -168,6 +178,7 @@ theorem principal_add_isLimit {o : Ordinal} (ho₁ : 1 < o) (ho : Principal (·
       rwa [← add_one_eq_succ, add_le_add_iff_left, one_le_iff_ne_zero]
 #align ordinal.principal_add_is_limit Ordinal.principal_add_isLimit
 
+#print Ordinal.principal_add_iff_add_left_eq_self /-
 theorem principal_add_iff_add_left_eq_self {o : Ordinal} :
     Principal (· + ·) o ↔ ∀ a < o, a + o = o :=
   by
@@ -181,7 +192,9 @@ theorem principal_add_iff_add_left_eq_self {o : Ordinal} :
   · rw [← h a hao]
     exact (add_is_normal a).StrictMono hbo
 #align ordinal.principal_add_iff_add_left_eq_self Ordinal.principal_add_iff_add_left_eq_self
+-/
 
+#print Ordinal.exists_lt_add_of_not_principal_add /-
 theorem exists_lt_add_of_not_principal_add {a} (ha : ¬Principal (· + ·) a) :
     ∃ (b c : _)(hb : b < a)(hc : c < a), b + c = a :=
   by
@@ -193,7 +206,9 @@ theorem exists_lt_add_of_not_principal_add {a} (ha : ¬Principal (· + ·) a) :
   rw [← sub_le, hab] at H
   exact H.not_lt hc
 #align ordinal.exists_lt_add_of_not_principal_add Ordinal.exists_lt_add_of_not_principal_add
+-/
 
+#print Ordinal.principal_add_iff_add_lt_ne_self /-
 theorem principal_add_iff_add_lt_ne_self {a} :
     Principal (· + ·) a ↔ ∀ ⦃b c⦄, b < a → c < a → b + c ≠ a :=
   ⟨fun ha b c hb hc => (ha hb hc).Ne, fun H =>
@@ -202,7 +217,9 @@ theorem principal_add_iff_add_lt_ne_self {a} :
     rcases exists_lt_add_of_not_principal_add ha with ⟨b, c, hb, hc, rfl⟩
     exact (H hb hc).irrefl⟩
 #align ordinal.principal_add_iff_add_lt_ne_self Ordinal.principal_add_iff_add_lt_ne_self
+-/
 
+#print Ordinal.add_omega /-
 theorem add_omega {a : Ordinal} (h : a < omega) : a + omega = omega :=
   by
   rcases lt_omega.1 h with ⟨n, rfl⟩
@@ -210,6 +227,7 @@ theorem add_omega {a : Ordinal} (h : a < omega) : a + omega = omega :=
   · rw [Nat.cast_zero, zero_add]
   · rwa [Nat.cast_succ, add_assoc, one_add_of_omega_le (le_refl _)]
 #align ordinal.add_omega Ordinal.add_omega
+-/
 
 #print Ordinal.principal_add_omega /-
 theorem principal_add_omega : Principal (· + ·) omega :=
Diff
@@ -71,12 +71,6 @@ theorem principal_zero {op : Ordinal → Ordinal → Ordinal} : Principal op 0 :
 #align ordinal.principal_zero Ordinal.principal_zero
 -/
 
-/- warning: ordinal.principal_one_iff -> Ordinal.principal_one_iff is a dubious translation:
-lean 3 declaration is
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 @[simp]
 theorem principal_one_iff {op : Ordinal → Ordinal → Ordinal} : Principal op 1 ↔ op 0 0 = 0 :=
   by
@@ -86,12 +80,6 @@ theorem principal_one_iff {op : Ordinal → Ordinal → Ordinal} : Principal op
   · rwa [lt_one_iff_zero, ha, hb] at *
 #align ordinal.principal_one_iff Ordinal.principal_one_iff
 
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 theorem Principal.iterate_lt {op : Ordinal → Ordinal → Ordinal} {a o : Ordinal} (hao : a < o)
     (ho : Principal op o) (n : ℕ) : (op a^[n]) a < o :=
   by
@@ -100,12 +88,6 @@ theorem Principal.iterate_lt {op : Ordinal → Ordinal → Ordinal} {a o : Ordin
   · rw [Function.iterate_succ']; exact ho hao hn
 #align ordinal.principal.iterate_lt Ordinal.Principal.iterate_lt
 
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 theorem op_eq_self_of_principal {op : Ordinal → Ordinal → Ordinal} {a o : Ordinal.{u}} (hao : a < o)
     (H : IsNormal (op a)) (ho : Principal op o) (ho' : IsLimit o) : op a o = o :=
   by
@@ -114,12 +96,6 @@ theorem op_eq_self_of_principal {op : Ordinal → Ordinal → Ordinal} {a o : Or
   exact fun b hbo => (ho hao hbo).le
 #align ordinal.op_eq_self_of_principal Ordinal.op_eq_self_of_principal
 
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 theorem nfp_le_of_principal {op : Ordinal → Ordinal → Ordinal} {a o : Ordinal} (hao : a < o)
     (ho : Principal op o) : nfp (op a) a ≤ o :=
   nfp_le fun n => (ho.iterate_lt hao n).le
@@ -136,12 +112,6 @@ def blsub₂ (op : Ordinal → Ordinal → Ordinal) (o : Ordinal) : Ordinal :=
 #align ordinal.blsub₂ Ordinal.blsub₂
 -/
 
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 theorem lt_blsub₂ (op : Ordinal → Ordinal → Ordinal) {o : Ordinal} {a b : Ordinal} (ha : a < o)
     (hb : b < o) : op a b < blsub₂ op o :=
   by
@@ -167,12 +137,6 @@ theorem principal_nfp_blsub₂ (op : Ordinal → Ordinal → Ordinal) (o : Ordin
 #align ordinal.principal_nfp_blsub₂ Ordinal.principal_nfp_blsub₂
 -/
 
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 theorem unbounded_principal (op : Ordinal → Ordinal → Ordinal) :
     Set.Unbounded (· < ·) { o | Principal op o } := fun o =>
   ⟨_, principal_nfp_blsub₂ op o, (le_nfp _ o).not_lt⟩
@@ -181,22 +145,10 @@ theorem unbounded_principal (op : Ordinal → Ordinal → Ordinal) :
 /-! #### Additive principal ordinals -/
 
 
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 theorem principal_add_one : Principal (· + ·) 1 :=
   principal_one_iff.2 <| zero_add 0
 #align ordinal.principal_add_one Ordinal.principal_add_one
 
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 theorem principal_add_of_le_one {o : Ordinal} (ho : o ≤ 1) : Principal (· + ·) o :=
   by
   rcases le_one_iff.1 ho with (rfl | rfl)
@@ -204,12 +156,6 @@ theorem principal_add_of_le_one {o : Ordinal} (ho : o ≤ 1) : Principal (· + 
   · exact principal_add_one
 #align ordinal.principal_add_of_le_one Ordinal.principal_add_of_le_one
 
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 theorem principal_add_isLimit {o : Ordinal} (ho₁ : 1 < o) (ho : Principal (· + ·) o) : o.IsLimit :=
   by
   refine' ⟨fun ho₀ => _, fun a hao => _⟩
@@ -222,12 +168,6 @@ theorem principal_add_isLimit {o : Ordinal} (ho₁ : 1 < o) (ho : Principal (·
       rwa [← add_one_eq_succ, add_le_add_iff_left, one_le_iff_ne_zero]
 #align ordinal.principal_add_is_limit Ordinal.principal_add_isLimit
 
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 theorem principal_add_iff_add_left_eq_self {o : Ordinal} :
     Principal (· + ·) o ↔ ∀ a < o, a + o = o :=
   by
@@ -242,12 +182,6 @@ theorem principal_add_iff_add_left_eq_self {o : Ordinal} :
     exact (add_is_normal a).StrictMono hbo
 #align ordinal.principal_add_iff_add_left_eq_self Ordinal.principal_add_iff_add_left_eq_self
 
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 theorem exists_lt_add_of_not_principal_add {a} (ha : ¬Principal (· + ·) a) :
     ∃ (b c : _)(hb : b < a)(hc : c < a), b + c = a :=
   by
@@ -260,12 +194,6 @@ theorem exists_lt_add_of_not_principal_add {a} (ha : ¬Principal (· + ·) a) :
   exact H.not_lt hc
 #align ordinal.exists_lt_add_of_not_principal_add Ordinal.exists_lt_add_of_not_principal_add
 
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 theorem principal_add_iff_add_lt_ne_self {a} :
     Principal (· + ·) a ↔ ∀ ⦃b c⦄, b < a → c < a → b + c ≠ a :=
   ⟨fun ha b c hb hc => (ha hb hc).Ne, fun H =>
@@ -275,12 +203,6 @@ theorem principal_add_iff_add_lt_ne_self {a} :
     exact (H hb hc).irrefl⟩
 #align ordinal.principal_add_iff_add_lt_ne_self Ordinal.principal_add_iff_add_lt_ne_self
 
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 theorem add_omega {a : Ordinal} (h : a < omega) : a + omega = omega :=
   by
   rcases lt_omega.1 h with ⟨n, rfl⟩
@@ -295,12 +217,6 @@ theorem principal_add_omega : Principal (· + ·) omega :=
 #align ordinal.principal_add_omega Ordinal.principal_add_omega
 -/
 
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 theorem add_omega_opow {a b : Ordinal} (h : a < (omega^b)) : a + (omega^b) = (omega^b) :=
   by
   refine' le_antisymm _ (le_add_left _ _)
@@ -320,22 +236,10 @@ theorem add_omega_opow {a b : Ordinal} (h : a < (omega^b)) : a + (omega^b) = (om
             (opow_le_opow_right omega_pos <| le_of_lt <| max_lt xb yb))
 #align ordinal.add_omega_opow Ordinal.add_omega_opow
 
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 theorem principal_add_omega_opow (o : Ordinal) : Principal (· + ·) (omega^o) :=
   principal_add_iff_add_left_eq_self.2 fun a => add_omega_opow
 #align ordinal.principal_add_omega_opow Ordinal.principal_add_omega_opow
 
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 /-- The main characterization theorem for additive principal ordinals. -/
 theorem principal_add_iff_zero_or_omega_opow {o : Ordinal} :
     Principal (· + ·) o ↔ o = 0 ∨ ∃ a, o = (omega^a) :=
@@ -359,12 +263,6 @@ theorem principal_add_iff_zero_or_omega_opow {o : Ordinal} :
     simp only [Nat.cast_succ, mul_add_one, add_assoc, this, IH]
 #align ordinal.principal_add_iff_zero_or_omega_opow Ordinal.principal_add_iff_zero_or_omega_opow
 
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 theorem opow_principal_add_of_principal_add {a} (ha : Principal (· + ·) a) (b : Ordinal) :
     Principal (· + ·) (a^b) :=
   by
@@ -375,22 +273,10 @@ theorem opow_principal_add_of_principal_add {a} (ha : Principal (· + ·) a) (b
   · rw [← opow_mul]; exact principal_add_omega_opow _
 #align ordinal.opow_principal_add_of_principal_add Ordinal.opow_principal_add_of_principal_add
 
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 theorem add_absorp {a b c : Ordinal} (h₁ : a < (omega^b)) (h₂ : (omega^b) ≤ c) : a + c = c := by
   rw [← Ordinal.add_sub_cancel_of_le h₂, ← add_assoc, add_omega_opow h₁]
 #align ordinal.add_absorp Ordinal.add_absorp
 
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 theorem mul_principal_add_is_principal_add (a : Ordinal.{u}) {b : Ordinal.{u}} (hb₁ : b ≠ 1)
     (hb : Principal (· + ·) b) : Principal (· + ·) (a * b) :=
   by
@@ -414,22 +300,10 @@ theorem mul_principal_add_is_principal_add (a : Ordinal.{u}) {b : Ordinal.{u}} (
 /-! #### Multiplicative principal ordinals -/
 
 
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 theorem principal_mul_one : Principal (· * ·) 1 := by rw [principal_one_iff];
   exact MulZeroClass.zero_mul _
 #align ordinal.principal_mul_one Ordinal.principal_mul_one
 
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 theorem principal_mul_two : Principal (· * ·) 2 := fun a b ha hb =>
   by
   have h₂ : succ (1 : Ordinal) = 2 := rfl
@@ -438,12 +312,6 @@ theorem principal_mul_two : Principal (· * ·) 2 := fun a b ha hb =>
   exact (mul_one 1).symm
 #align ordinal.principal_mul_two Ordinal.principal_mul_two
 
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 theorem principal_mul_of_le_two {o : Ordinal} (ho : o ≤ 2) : Principal (· * ·) o :=
   by
   rcases lt_or_eq_of_le ho with (ho | rfl)
@@ -456,12 +324,6 @@ theorem principal_mul_of_le_two {o : Ordinal} (ho : o ≤ 2) : Principal (· * 
   · exact principal_mul_two
 #align ordinal.principal_mul_of_le_two Ordinal.principal_mul_of_le_two
 
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 theorem principal_add_of_principal_mul {o : Ordinal} (ho : Principal (· * ·) o) (ho₂ : o ≠ 2) :
     Principal (· + ·) o := by
   cases' lt_or_gt_of_ne ho₂ with ho₁ ho₂
@@ -473,23 +335,11 @@ theorem principal_add_of_principal_mul {o : Ordinal} (ho : Principal (· * ·) o
     exact add_le_add (le_max_left a b) (le_max_right a b)
 #align ordinal.principal_add_of_principal_mul Ordinal.principal_add_of_principal_mul
 
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 theorem principal_mul_isLimit {o : Ordinal.{u}} (ho₂ : 2 < o) (ho : Principal (· * ·) o) :
     o.IsLimit :=
   principal_add_isLimit ((lt_succ 1).trans ho₂) (principal_add_of_principal_mul ho (ne_of_gt ho₂))
 #align ordinal.principal_mul_is_limit Ordinal.principal_mul_isLimit
 
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 theorem principal_mul_iff_mul_left_eq {o : Ordinal} :
     Principal (· * ·) o ↔ ∀ a, 0 < a → a < o → a * o = o :=
   by
@@ -507,33 +357,15 @@ theorem principal_mul_iff_mul_left_eq {o : Ordinal} :
     exact (mul_is_normal ha).StrictMono hbo
 #align ordinal.principal_mul_iff_mul_left_eq Ordinal.principal_mul_iff_mul_left_eq
 
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 theorem principal_mul_omega : Principal (· * ·) omega := fun a b ha hb =>
   match a, b, lt_omega.1 ha, lt_omega.1 hb with
   | _, _, ⟨m, rfl⟩, ⟨n, rfl⟩ => by rw [← nat_cast_mul]; apply nat_lt_omega
 #align ordinal.principal_mul_omega Ordinal.principal_mul_omega
 
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 theorem mul_omega {a : Ordinal} (a0 : 0 < a) (ha : a < omega) : a * omega = omega :=
   principal_mul_iff_mul_left_eq.1 principal_mul_omega a a0 ha
 #align ordinal.mul_omega Ordinal.mul_omega
 
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 theorem mul_lt_omega_opow {a b c : Ordinal} (c0 : 0 < c) (ha : a < (omega^c)) (hb : b < omega) :
     a * b < (omega^c) :=
   by
@@ -550,12 +382,6 @@ theorem mul_lt_omega_opow {a b c : Ordinal} (c0 : 0 < c) (ha : a < (omega^c)) (h
     exact l.2 _ hx
 #align ordinal.mul_lt_omega_opow Ordinal.mul_lt_omega_opow
 
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 theorem mul_omega_opow_opow {a b : Ordinal} (a0 : 0 < a) (h : a < (omega^omega^b)) :
     a * (omega^omega^b) = (omega^omega^b) :=
   by
@@ -568,22 +394,10 @@ theorem mul_omega_opow_opow {a b : Ordinal} (a0 : 0 < a) (h : a < (omega^omega^b
   rw [← opow_add, add_omega_opow xb]
 #align ordinal.mul_omega_opow_opow Ordinal.mul_omega_opow_opow
 
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 theorem principal_mul_omega_opow_opow (o : Ordinal) : Principal (· * ·) (omega^omega^o) :=
   principal_mul_iff_mul_left_eq.2 fun a => mul_omega_opow_opow
 #align ordinal.principal_mul_omega_opow_opow Ordinal.principal_mul_omega_opow_opow
 
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 theorem principal_add_of_principal_mul_opow {o b : Ordinal} (hb : 1 < b)
     (ho : Principal (· * ·) (b^o)) : Principal (· + ·) o := fun x y hx hy =>
   by
@@ -591,12 +405,6 @@ theorem principal_add_of_principal_mul_opow {o b : Ordinal} (hb : 1 < b)
   rwa [← opow_add, opow_lt_opow_iff_right hb] at this
 #align ordinal.principal_add_of_principal_mul_opow Ordinal.principal_add_of_principal_mul_opow
 
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 /-- The main characterization theorem for multiplicative principal ordinals. -/
 theorem principal_mul_iff_le_two_or_omega_opow_opow {o : Ordinal} :
     Principal (· * ·) o ↔ o ≤ 2 ∨ ∃ a, o = (omega^omega^a) :=
@@ -618,22 +426,10 @@ theorem principal_mul_iff_le_two_or_omega_opow_opow {o : Ordinal} :
     · exact principal_mul_omega_opow_opow a
 #align ordinal.principal_mul_iff_le_two_or_omega_opow_opow Ordinal.principal_mul_iff_le_two_or_omega_opow_opow
 
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 theorem mul_omega_dvd {a : Ordinal} (a0 : 0 < a) (ha : a < omega) : ∀ {b}, omega ∣ b → a * b = b
   | _, ⟨b, rfl⟩ => by rw [← mul_assoc, mul_omega a0 ha]
 #align ordinal.mul_omega_dvd Ordinal.mul_omega_dvd
 
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 theorem mul_eq_opow_log_succ {a b : Ordinal.{u}} (ha : a ≠ 0) (hb : Principal (· * ·) b)
     (hb₂ : 2 < b) : a * b = (b^succ (log b a)) :=
   by
@@ -655,23 +451,11 @@ theorem mul_eq_opow_log_succ {a b : Ordinal.{u}} (ha : a ≠ 0) (hb : Principal
 /-! #### Exponential principal ordinals -/
 
 
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 theorem principal_opow_omega : Principal (·^·) omega := fun a b ha hb =>
   match a, b, lt_omega.1 ha, lt_omega.1 hb with
   | _, _, ⟨m, rfl⟩, ⟨n, rfl⟩ => by simp_rw [← nat_cast_opow]; apply nat_lt_omega
 #align ordinal.principal_opow_omega Ordinal.principal_opow_omega
 
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-Case conversion may be inaccurate. Consider using '#align ordinal.opow_omega Ordinal.opow_omegaₓ'. -/
 theorem opow_omega {a : Ordinal} (a1 : 1 < a) (h : a < omega) : (a^omega) = omega :=
   le_antisymm
     ((opow_le_of_limit (one_le_iff_ne_zero.1 <| le_of_lt a1) omega_isLimit).2 fun b hb =>
Diff
@@ -97,8 +97,7 @@ theorem Principal.iterate_lt {op : Ordinal → Ordinal → Ordinal} {a o : Ordin
   by
   induction' n with n hn
   · rwa [Function.iterate_zero]
-  · rw [Function.iterate_succ']
-    exact ho hao hn
+  · rw [Function.iterate_succ']; exact ho hao hn
 #align ordinal.principal.iterate_lt Ordinal.Principal.iterate_lt
 
 /- warning: ordinal.op_eq_self_of_principal -> Ordinal.op_eq_self_of_principal is a dubious translation:
@@ -352,14 +351,11 @@ theorem principal_add_iff_zero_or_omega_opow {o : Ordinal} :
     have := lt_opow_succ_log_self one_lt_omega o
     rw [opow_succ, lt_mul_of_limit omega_is_limit] at this
     rcases this with ⟨a, ao, h'⟩
-    rcases lt_omega.1 ao with ⟨n, rfl⟩
-    clear ao
-    revert h'
-    apply not_lt_of_le
+    rcases lt_omega.1 ao with ⟨n, rfl⟩; clear ao
+    revert h'; apply not_lt_of_le
     suffices e : (omega^log omega o) * ↑n + o = o
     · simpa only [e] using le_add_right ((omega^log omega o) * ↑n) o
-    induction' n with n IH
-    · simp only [Nat.cast_zero, MulZeroClass.mul_zero, zero_add]
+    induction' n with n IH; · simp only [Nat.cast_zero, MulZeroClass.mul_zero, zero_add]
     simp only [Nat.cast_succ, mul_add_one, add_assoc, this, IH]
 #align ordinal.principal_add_iff_zero_or_omega_opow Ordinal.principal_add_iff_zero_or_omega_opow
 
@@ -374,11 +370,9 @@ theorem opow_principal_add_of_principal_add {a} (ha : Principal (· + ·) a) (b
   by
   rcases principal_add_iff_zero_or_omega_opow.1 ha with (rfl | ⟨c, rfl⟩)
   · rcases eq_or_ne b 0 with (rfl | hb)
-    · rw [opow_zero]
-      exact principal_add_one
+    · rw [opow_zero]; exact principal_add_one
     · rwa [zero_opow hb]
-  · rw [← opow_mul]
-    exact principal_add_omega_opow _
+  · rw [← opow_mul]; exact principal_add_omega_opow _
 #align ordinal.opow_principal_add_of_principal_add Ordinal.opow_principal_add_of_principal_add
 
 /- warning: ordinal.add_absorp -> Ordinal.add_absorp is a dubious translation:
@@ -426,9 +420,7 @@ lean 3 declaration is
 but is expected to have type
   Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3104 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3106 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3104 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3106) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (One.toOfNat1.{succ u1} Ordinal.{u1} Ordinal.one.{u1}))
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_mul_one Ordinal.principal_mul_oneₓ'. -/
-theorem principal_mul_one : Principal (· * ·) 1 :=
-  by
-  rw [principal_one_iff]
+theorem principal_mul_one : Principal (· * ·) 1 := by rw [principal_one_iff];
   exact MulZeroClass.zero_mul _
 #align ordinal.principal_mul_one Ordinal.principal_mul_one
 
@@ -509,8 +501,7 @@ theorem principal_mul_iff_mul_left_eq {o : Ordinal} :
         rwa [lt_succ_iff] at this
       · rwa [← succ_le_iff, succ_zero] at ha₀
     · exact op_eq_self_of_principal hao (mul_is_normal ha₀) h (principal_mul_is_limit ho h)
-  · rcases eq_or_ne a 0 with (rfl | ha)
-    · rwa [MulZeroClass.zero_mul]
+  · rcases eq_or_ne a 0 with (rfl | ha); · rwa [MulZeroClass.zero_mul]
     rw [← Ordinal.pos_iff_ne_zero] at ha
     rw [← h a ha hao]
     exact (mul_is_normal ha).StrictMono hbo
@@ -524,9 +515,7 @@ but is expected to have type
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_mul_omega Ordinal.principal_mul_omegaₓ'. -/
 theorem principal_mul_omega : Principal (· * ·) omega := fun a b ha hb =>
   match a, b, lt_omega.1 ha, lt_omega.1 hb with
-  | _, _, ⟨m, rfl⟩, ⟨n, rfl⟩ => by
-    rw [← nat_cast_mul]
-    apply nat_lt_omega
+  | _, _, ⟨m, rfl⟩, ⟨n, rfl⟩ => by rw [← nat_cast_mul]; apply nat_lt_omega
 #align ordinal.principal_mul_omega Ordinal.principal_mul_omega
 
 /- warning: ordinal.mul_omega -> Ordinal.mul_omega is a dubious translation:
@@ -570,9 +559,7 @@ Case conversion may be inaccurate. Consider using '#align ordinal.mul_omega_opow
 theorem mul_omega_opow_opow {a b : Ordinal} (a0 : 0 < a) (h : a < (omega^omega^b)) :
     a * (omega^omega^b) = (omega^omega^b) :=
   by
-  by_cases b0 : b = 0;
-  · rw [b0, opow_zero, opow_one] at h⊢
-    exact mul_omega a0 h
+  by_cases b0 : b = 0; · rw [b0, opow_zero, opow_one] at h⊢; exact mul_omega a0 h
   refine'
     le_antisymm _
       (by simpa only [one_mul] using mul_le_mul_right' (one_le_iff_pos.2 a0) (omega^omega^b))
@@ -676,9 +663,7 @@ but is expected to have type
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_opow_omega Ordinal.principal_opow_omegaₓ'. -/
 theorem principal_opow_omega : Principal (·^·) omega := fun a b ha hb =>
   match a, b, lt_omega.1 ha, lt_omega.1 hb with
-  | _, _, ⟨m, rfl⟩, ⟨n, rfl⟩ => by
-    simp_rw [← nat_cast_opow]
-    apply nat_lt_omega
+  | _, _, ⟨m, rfl⟩, ⟨n, rfl⟩ => by simp_rw [← nat_cast_opow]; apply nat_lt_omega
 #align ordinal.principal_opow_omega Ordinal.principal_opow_omega
 
 /- warning: ordinal.opow_omega -> Ordinal.opow_omega is a dubious translation:
Diff
@@ -86,7 +86,12 @@ theorem principal_one_iff {op : Ordinal → Ordinal → Ordinal} : Principal op
   · rwa [lt_one_iff_zero, ha, hb] at *
 #align ordinal.principal_one_iff Ordinal.principal_one_iff
 
-#print Ordinal.Principal.iterate_lt /-
+/- warning: ordinal.principal.iterate_lt -> Ordinal.Principal.iterate_lt is a dubious translation:
+lean 3 declaration is
+  forall {op : Ordinal.{u1} -> Ordinal.{u1} -> Ordinal.{u1}} {a : Ordinal.{u1}} {o : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a o) -> (Ordinal.Principal.{u1} op o) -> (forall (n : Nat), LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (Nat.iterate.{succ (succ u1)} Ordinal.{u1} (op a) n a) o)
+but is expected to have type
+  forall {op : Ordinal.{u1} -> Ordinal.{u1} -> Ordinal.{u1}} {a : Ordinal.{u1}} {o : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a o) -> (Ordinal.Principal.{u1} op o) -> (forall (n : Nat), LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (Nat.iterate.{succ (succ u1)} Ordinal.{u1} (op a) n a) o)
+Case conversion may be inaccurate. Consider using '#align ordinal.principal.iterate_lt Ordinal.Principal.iterate_ltₓ'. -/
 theorem Principal.iterate_lt {op : Ordinal → Ordinal → Ordinal} {a o : Ordinal} (hao : a < o)
     (ho : Principal op o) (n : ℕ) : (op a^[n]) a < o :=
   by
@@ -95,9 +100,13 @@ theorem Principal.iterate_lt {op : Ordinal → Ordinal → Ordinal} {a o : Ordin
   · rw [Function.iterate_succ']
     exact ho hao hn
 #align ordinal.principal.iterate_lt Ordinal.Principal.iterate_lt
--/
 
-#print Ordinal.op_eq_self_of_principal /-
+/- warning: ordinal.op_eq_self_of_principal -> Ordinal.op_eq_self_of_principal is a dubious translation:
+lean 3 declaration is
+  forall {op : Ordinal.{u1} -> Ordinal.{u1} -> Ordinal.{u1}} {a : Ordinal.{u1}} {o : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a o) -> (Ordinal.IsNormal.{u1, u1} (op a)) -> (Ordinal.Principal.{u1} op o) -> (Ordinal.IsLimit.{u1} o) -> (Eq.{succ (succ u1)} Ordinal.{u1} (op a o) o)
+but is expected to have type
+  forall {op : Ordinal.{u1} -> Ordinal.{u1} -> Ordinal.{u1}} {a : Ordinal.{u1}} {o : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a o) -> (Ordinal.IsNormal.{u1, u1} (op a)) -> (Ordinal.Principal.{u1} op o) -> (Ordinal.IsLimit.{u1} o) -> (Eq.{succ (succ u1)} Ordinal.{u1} (op a o) o)
+Case conversion may be inaccurate. Consider using '#align ordinal.op_eq_self_of_principal Ordinal.op_eq_self_of_principalₓ'. -/
 theorem op_eq_self_of_principal {op : Ordinal → Ordinal → Ordinal} {a o : Ordinal.{u}} (hao : a < o)
     (H : IsNormal (op a)) (ho : Principal op o) (ho' : IsLimit o) : op a o = o :=
   by
@@ -105,14 +114,17 @@ theorem op_eq_self_of_principal {op : Ordinal → Ordinal → Ordinal} {a o : Or
   rw [← IsNormal.bsup_eq.{u, u} H ho', bsup_le_iff]
   exact fun b hbo => (ho hao hbo).le
 #align ordinal.op_eq_self_of_principal Ordinal.op_eq_self_of_principal
--/
 
-#print Ordinal.nfp_le_of_principal /-
+/- warning: ordinal.nfp_le_of_principal -> Ordinal.nfp_le_of_principal is a dubious translation:
+lean 3 declaration is
+  forall {op : Ordinal.{u1} -> Ordinal.{u1} -> Ordinal.{u1}} {a : Ordinal.{u1}} {o : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a o) -> (Ordinal.Principal.{u1} op o) -> (LE.le.{succ u1} Ordinal.{u1} (Preorder.toHasLe.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (Ordinal.nfp.{u1} (op a) a) o)
+but is expected to have type
+  forall {op : Ordinal.{u1} -> Ordinal.{u1} -> Ordinal.{u1}} {a : Ordinal.{u1}} {o : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a o) -> (Ordinal.Principal.{u1} op o) -> (LE.le.{succ u1} Ordinal.{u1} (Preorder.toLE.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (Ordinal.nfp.{u1} (op a) a) o)
+Case conversion may be inaccurate. Consider using '#align ordinal.nfp_le_of_principal Ordinal.nfp_le_of_principalₓ'. -/
 theorem nfp_le_of_principal {op : Ordinal → Ordinal → Ordinal} {a o : Ordinal} (hao : a < o)
     (ho : Principal op o) : nfp (op a) a ≤ o :=
   nfp_le fun n => (ho.iterate_lt hao n).le
 #align ordinal.nfp_le_of_principal Ordinal.nfp_le_of_principal
--/
 
 /-! ### Principal ordinals are unbounded -/
 
@@ -125,7 +137,12 @@ def blsub₂ (op : Ordinal → Ordinal → Ordinal) (o : Ordinal) : Ordinal :=
 #align ordinal.blsub₂ Ordinal.blsub₂
 -/
 
-#print Ordinal.lt_blsub₂ /-
+/- warning: ordinal.lt_blsub₂ -> Ordinal.lt_blsub₂ is a dubious translation:
+lean 3 declaration is
+  forall (op : Ordinal.{u1} -> Ordinal.{u1} -> Ordinal.{max u1 u2}) {o : Ordinal.{u1}} {a : Ordinal.{u1}} {b : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a o) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) b o) -> (LT.lt.{succ (max u1 u2)} Ordinal.{max u1 u2} (Preorder.toHasLt.{succ (max u1 u2)} Ordinal.{max u1 u2} (PartialOrder.toPreorder.{succ (max u1 u2)} Ordinal.{max u1 u2} Ordinal.partialOrder.{max u1 u2})) (op a b) (Ordinal.blsub₂.{u1, u2} op o))
+but is expected to have type
+  forall (op : Ordinal.{u1} -> Ordinal.{u1} -> Ordinal.{max u1 u2}) {o : Ordinal.{u1}} {a : Ordinal.{u1}} {b : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a o) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) b o) -> (LT.lt.{max (succ u1) (succ u2)} Ordinal.{max u1 u2} (Preorder.toLT.{max (succ u1) (succ u2)} Ordinal.{max u1 u2} (PartialOrder.toPreorder.{max (succ u1) (succ u2)} Ordinal.{max u1 u2} Ordinal.partialOrder.{max u1 u2})) (op a b) (Ordinal.blsub₂.{u1, u2} op o))
+Case conversion may be inaccurate. Consider using '#align ordinal.lt_blsub₂ Ordinal.lt_blsub₂ₓ'. -/
 theorem lt_blsub₂ (op : Ordinal → Ordinal → Ordinal) {o : Ordinal} {a b : Ordinal} (ha : a < o)
     (hb : b < o) : op a b < blsub₂ op o :=
   by
@@ -133,7 +150,6 @@ theorem lt_blsub₂ (op : Ordinal → Ordinal → Ordinal) {o : Ordinal} {a b :
       (Prod.mk (enum (· < ·) a (by rwa [type_lt])) (enum (· < ·) b (by rwa [type_lt])))
   simp only [typein_enum]
 #align ordinal.lt_blsub₂ Ordinal.lt_blsub₂
--/
 
 #print Ordinal.principal_nfp_blsub₂ /-
 theorem principal_nfp_blsub₂ (op : Ordinal → Ordinal → Ordinal) (o : Ordinal) :
@@ -152,12 +168,16 @@ theorem principal_nfp_blsub₂ (op : Ordinal → Ordinal → Ordinal) (o : Ordin
 #align ordinal.principal_nfp_blsub₂ Ordinal.principal_nfp_blsub₂
 -/
 
-#print Ordinal.unbounded_principal /-
+/- warning: ordinal.unbounded_principal -> Ordinal.unbounded_principal is a dubious translation:
+lean 3 declaration is
+  forall (op : Ordinal.{u1} -> Ordinal.{u1} -> Ordinal.{u1}), Set.Unbounded.{succ u1} Ordinal.{u1} (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1}))) (setOf.{succ u1} Ordinal.{u1} (fun (o : Ordinal.{u1}) => Ordinal.Principal.{u1} op o))
+but is expected to have type
+  forall (op : Ordinal.{u1} -> Ordinal.{u1} -> Ordinal.{u1}), Set.Unbounded.{succ u1} Ordinal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1049 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1051 : Ordinal.{u1}) => LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1049 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1051) (setOf.{succ u1} Ordinal.{u1} (fun (o : Ordinal.{u1}) => Ordinal.Principal.{u1} op o))
+Case conversion may be inaccurate. Consider using '#align ordinal.unbounded_principal Ordinal.unbounded_principalₓ'. -/
 theorem unbounded_principal (op : Ordinal → Ordinal → Ordinal) :
     Set.Unbounded (· < ·) { o | Principal op o } := fun o =>
   ⟨_, principal_nfp_blsub₂ op o, (le_nfp _ o).not_lt⟩
 #align ordinal.unbounded_principal Ordinal.unbounded_principal
--/
 
 /-! #### Additive principal ordinals -/
 
@@ -174,7 +194,7 @@ theorem principal_add_one : Principal (· + ·) 1 :=
 
 /- warning: ordinal.principal_add_of_le_one -> Ordinal.principal_add_of_le_one is a dubious translation:
 lean 3 declaration is
-  forall {o : Ordinal.{u1}}, (LE.le.{succ u1} Ordinal.{u1} (Preorder.toLE.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) o (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (OfNat.mk.{succ u1} Ordinal.{u1} 1 (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1})))) -> (Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) o)
+  forall {o : Ordinal.{u1}}, (LE.le.{succ u1} Ordinal.{u1} (Preorder.toHasLe.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) o (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (OfNat.mk.{succ u1} Ordinal.{u1} 1 (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1})))) -> (Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) o)
 but is expected to have type
   forall {o : Ordinal.{u1}}, (LE.le.{succ u1} Ordinal.{u1} (Preorder.toLE.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) o (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (One.toOfNat1.{succ u1} Ordinal.{u1} Ordinal.one.{u1}))) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1124 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1126 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1124 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1126) o)
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_add_of_le_one Ordinal.principal_add_of_le_oneₓ'. -/
@@ -187,7 +207,7 @@ theorem principal_add_of_le_one {o : Ordinal} (ho : o ≤ 1) : Principal (· + 
 
 /- warning: ordinal.principal_add_is_limit -> Ordinal.principal_add_isLimit is a dubious translation:
 lean 3 declaration is
-  forall {o : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (OfNat.mk.{succ u1} Ordinal.{u1} 1 (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1}))) o) -> (Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) o) -> (Ordinal.IsLimit.{u1} o)
+  forall {o : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (OfNat.mk.{succ u1} Ordinal.{u1} 1 (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1}))) o) -> (Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) o) -> (Ordinal.IsLimit.{u1} o)
 but is expected to have type
   forall {o : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (One.toOfNat1.{succ u1} Ordinal.{u1} Ordinal.one.{u1})) o) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1166 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1168 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1166 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1168) o) -> (Ordinal.IsLimit.{u1} o)
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_add_is_limit Ordinal.principal_add_isLimitₓ'. -/
@@ -203,7 +223,12 @@ theorem principal_add_isLimit {o : Ordinal} (ho₁ : 1 < o) (ho : Principal (·
       rwa [← add_one_eq_succ, add_le_add_iff_left, one_le_iff_ne_zero]
 #align ordinal.principal_add_is_limit Ordinal.principal_add_isLimit
 
-#print Ordinal.principal_add_iff_add_left_eq_self /-
+/- warning: ordinal.principal_add_iff_add_left_eq_self -> Ordinal.principal_add_iff_add_left_eq_self is a dubious translation:
+lean 3 declaration is
+  forall {o : Ordinal.{u1}}, Iff (Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) o) (forall (a : Ordinal.{u1}), (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a o) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1}) a o) o))
+but is expected to have type
+  forall {o : Ordinal.{u1}}, Iff (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1330 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1332 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1330 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1332) o) (forall (a : Ordinal.{u1}), (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a o) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) a o) o))
+Case conversion may be inaccurate. Consider using '#align ordinal.principal_add_iff_add_left_eq_self Ordinal.principal_add_iff_add_left_eq_selfₓ'. -/
 theorem principal_add_iff_add_left_eq_self {o : Ordinal} :
     Principal (· + ·) o ↔ ∀ a < o, a + o = o :=
   by
@@ -217,9 +242,13 @@ theorem principal_add_iff_add_left_eq_self {o : Ordinal} :
   · rw [← h a hao]
     exact (add_is_normal a).StrictMono hbo
 #align ordinal.principal_add_iff_add_left_eq_self Ordinal.principal_add_iff_add_left_eq_self
--/
 
-#print Ordinal.exists_lt_add_of_not_principal_add /-
+/- warning: ordinal.exists_lt_add_of_not_principal_add -> Ordinal.exists_lt_add_of_not_principal_add is a dubious translation:
+lean 3 declaration is
+  forall {a : Ordinal.{u1}}, (Not (Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) a)) -> (Exists.{succ (succ u1)} Ordinal.{u1} (fun (b : Ordinal.{u1}) => Exists.{succ (succ u1)} Ordinal.{u1} (fun (c : Ordinal.{u1}) => Exists.{0} (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) b a) (fun (hb : LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) b a) => Exists.{0} (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) c a) (fun (hc : LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) c a) => Eq.{succ (succ u1)} Ordinal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1}) b c) a)))))
+but is expected to have type
+  forall {a : Ordinal.{u1}}, (Not (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1535 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1537 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1535 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1537) a)) -> (Exists.{succ (succ u1)} Ordinal.{u1} (fun (b : Ordinal.{u1}) => Exists.{succ (succ u1)} Ordinal.{u1} (fun (c : Ordinal.{u1}) => Exists.{0} (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) b a) (fun (hb : LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) b a) => Exists.{0} (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) c a) (fun (hc : LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) c a) => Eq.{succ (succ u1)} Ordinal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) b c) a)))))
+Case conversion may be inaccurate. Consider using '#align ordinal.exists_lt_add_of_not_principal_add Ordinal.exists_lt_add_of_not_principal_addₓ'. -/
 theorem exists_lt_add_of_not_principal_add {a} (ha : ¬Principal (· + ·) a) :
     ∃ (b c : _)(hb : b < a)(hc : c < a), b + c = a :=
   by
@@ -231,9 +260,13 @@ theorem exists_lt_add_of_not_principal_add {a} (ha : ¬Principal (· + ·) a) :
   rw [← sub_le, hab] at H
   exact H.not_lt hc
 #align ordinal.exists_lt_add_of_not_principal_add Ordinal.exists_lt_add_of_not_principal_add
--/
 
-#print Ordinal.principal_add_iff_add_lt_ne_self /-
+/- warning: ordinal.principal_add_iff_add_lt_ne_self -> Ordinal.principal_add_iff_add_lt_ne_self is a dubious translation:
+lean 3 declaration is
+  forall {a : Ordinal.{u1}}, Iff (Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) a) (forall {{b : Ordinal.{u1}}} {{c : Ordinal.{u1}}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) b a) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) c a) -> (Ne.{succ (succ u1)} Ordinal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1}) b c) a))
+but is expected to have type
+  forall {a : Ordinal.{u1}}, Iff (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1668 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1670 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1668 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1670) a) (forall {{b : Ordinal.{u1}}} {{c : Ordinal.{u1}}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) b a) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) c a) -> (Ne.{succ (succ u1)} Ordinal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) b c) a))
+Case conversion may be inaccurate. Consider using '#align ordinal.principal_add_iff_add_lt_ne_self Ordinal.principal_add_iff_add_lt_ne_selfₓ'. -/
 theorem principal_add_iff_add_lt_ne_self {a} :
     Principal (· + ·) a ↔ ∀ ⦃b c⦄, b < a → c < a → b + c ≠ a :=
   ⟨fun ha b c hb hc => (ha hb hc).Ne, fun H =>
@@ -242,9 +275,13 @@ theorem principal_add_iff_add_lt_ne_self {a} :
     rcases exists_lt_add_of_not_principal_add ha with ⟨b, c, hb, hc, rfl⟩
     exact (H hb hc).irrefl⟩
 #align ordinal.principal_add_iff_add_lt_ne_self Ordinal.principal_add_iff_add_lt_ne_self
--/
 
-#print Ordinal.add_omega /-
+/- warning: ordinal.add_omega -> Ordinal.add_omega is a dubious translation:
+lean 3 declaration is
+  forall {a : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a Ordinal.omega.{u1}) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1}) a Ordinal.omega.{u1}) Ordinal.omega.{u1})
+but is expected to have type
+  forall {a : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a Ordinal.omega.{u1}) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) a Ordinal.omega.{u1}) Ordinal.omega.{u1})
+Case conversion may be inaccurate. Consider using '#align ordinal.add_omega Ordinal.add_omegaₓ'. -/
 theorem add_omega {a : Ordinal} (h : a < omega) : a + omega = omega :=
   by
   rcases lt_omega.1 h with ⟨n, rfl⟩
@@ -252,7 +289,6 @@ theorem add_omega {a : Ordinal} (h : a < omega) : a + omega = omega :=
   · rw [Nat.cast_zero, zero_add]
   · rwa [Nat.cast_succ, add_assoc, one_add_of_omega_le (le_refl _)]
 #align ordinal.add_omega Ordinal.add_omega
--/
 
 #print Ordinal.principal_add_omega /-
 theorem principal_add_omega : Principal (· + ·) omega :=
@@ -262,7 +298,7 @@ theorem principal_add_omega : Principal (· + ·) omega :=
 
 /- warning: ordinal.add_omega_opow -> Ordinal.add_omega_opow is a dubious translation:
 lean 3 declaration is
-  forall {a : Ordinal.{u1}} {b : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} b)) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1}) a (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} b)) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} b))
+  forall {a : Ordinal.{u1}} {b : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} b)) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1}) a (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} b)) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} b))
 but is expected to have type
   forall {a : Ordinal.{u1}} {b : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} b)) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) a (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} b)) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} b))
 Case conversion may be inaccurate. Consider using '#align ordinal.add_omega_opow Ordinal.add_omega_opowₓ'. -/
@@ -347,7 +383,7 @@ theorem opow_principal_add_of_principal_add {a} (ha : Principal (· + ·) a) (b
 
 /- warning: ordinal.add_absorp -> Ordinal.add_absorp is a dubious translation:
 lean 3 declaration is
-  forall {a : Ordinal.{u1}} {b : Ordinal.{u1}} {c : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} b)) -> (LE.le.{succ u1} Ordinal.{u1} (Preorder.toLE.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} b) c) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1}) a c) c)
+  forall {a : Ordinal.{u1}} {b : Ordinal.{u1}} {c : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} b)) -> (LE.le.{succ u1} Ordinal.{u1} (Preorder.toHasLe.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} b) c) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1}) a c) c)
 but is expected to have type
   forall {a : Ordinal.{u1}} {b : Ordinal.{u1}} {c : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} b)) -> (LE.le.{succ u1} Ordinal.{u1} (Preorder.toLE.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} b) c) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) a c) c)
 Case conversion may be inaccurate. Consider using '#align ordinal.add_absorp Ordinal.add_absorpₓ'. -/
@@ -412,7 +448,7 @@ theorem principal_mul_two : Principal (· * ·) 2 := fun a b ha hb =>
 
 /- warning: ordinal.principal_mul_of_le_two -> Ordinal.principal_mul_of_le_two is a dubious translation:
 lean 3 declaration is
-  forall {o : Ordinal.{u1}}, (LE.le.{succ u1} Ordinal.{u1} (Preorder.toLE.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) o (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (OfNat.mk.{succ u1} Ordinal.{u1} 2 (bit0.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1} (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1}))))) -> (Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) o)
+  forall {o : Ordinal.{u1}}, (LE.le.{succ u1} Ordinal.{u1} (Preorder.toHasLe.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) o (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (OfNat.mk.{succ u1} Ordinal.{u1} 2 (bit0.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1} (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1}))))) -> (Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) o)
 but is expected to have type
   forall {o : Ordinal.{u1}}, (LE.le.{succ u1} Ordinal.{u1} (Preorder.toLE.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) o (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (instOfNat.{succ u1} Ordinal.{u1} 2 (AddMonoidWithOne.toNatCast.{succ u1} Ordinal.{u1} Ordinal.addMonoidWithOne.{u1}) (instAtLeastTwoHAddNatInstHAddInstAddNatOfNat (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0)))))) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3320 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3322 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3320 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3322) o)
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_mul_of_le_two Ordinal.principal_mul_of_le_twoₓ'. -/
@@ -447,7 +483,7 @@ theorem principal_add_of_principal_mul {o : Ordinal} (ho : Principal (· * ·) o
 
 /- warning: ordinal.principal_mul_is_limit -> Ordinal.principal_mul_isLimit is a dubious translation:
 lean 3 declaration is
-  forall {o : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (OfNat.mk.{succ u1} Ordinal.{u1} 2 (bit0.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1} (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1})))) o) -> (Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) o) -> (Ordinal.IsLimit.{u1} o)
+  forall {o : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (OfNat.mk.{succ u1} Ordinal.{u1} 2 (bit0.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1} (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1})))) o) -> (Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) o) -> (Ordinal.IsLimit.{u1} o)
 but is expected to have type
   forall {o : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (instOfNat.{succ u1} Ordinal.{u1} 2 (AddMonoidWithOne.toNatCast.{succ u1} Ordinal.{u1} Ordinal.addMonoidWithOne.{u1}) (instAtLeastTwoHAddNatInstHAddInstAddNatOfNat (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0))))) o) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3639 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3641 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3639 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3641) o) -> (Ordinal.IsLimit.{u1} o)
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_mul_is_limit Ordinal.principal_mul_isLimitₓ'. -/
@@ -458,7 +494,7 @@ theorem principal_mul_isLimit {o : Ordinal.{u}} (ho₂ : 2 < o) (ho : Principal
 
 /- warning: ordinal.principal_mul_iff_mul_left_eq -> Ordinal.principal_mul_iff_mul_left_eq is a dubious translation:
 lean 3 declaration is
-  forall {o : Ordinal.{u1}}, Iff (Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) o) (forall (a : Ordinal.{u1}), (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (OfNat.mk.{succ u1} Ordinal.{u1} 0 (Zero.zero.{succ u1} Ordinal.{u1} Ordinal.hasZero.{u1}))) a) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a o) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a o) o))
+  forall {o : Ordinal.{u1}}, Iff (Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) o) (forall (a : Ordinal.{u1}), (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (OfNat.mk.{succ u1} Ordinal.{u1} 0 (Zero.zero.{succ u1} Ordinal.{u1} Ordinal.hasZero.{u1}))) a) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a o) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a o) o))
 but is expected to have type
   forall {o : Ordinal.{u1}}, Iff (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3688 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3690 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3688 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3690) o) (forall (a : Ordinal.{u1}), (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (Zero.toOfNat0.{succ u1} Ordinal.{u1} Ordinal.zero.{u1})) a) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a o) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a o) o))
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_mul_iff_mul_left_eq Ordinal.principal_mul_iff_mul_left_eqₓ'. -/
@@ -495,7 +531,7 @@ theorem principal_mul_omega : Principal (· * ·) omega := fun a b ha hb =>
 
 /- warning: ordinal.mul_omega -> Ordinal.mul_omega is a dubious translation:
 lean 3 declaration is
-  forall {a : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (OfNat.mk.{succ u1} Ordinal.{u1} 0 (Zero.zero.{succ u1} Ordinal.{u1} Ordinal.hasZero.{u1}))) a) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a Ordinal.omega.{u1}) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a Ordinal.omega.{u1}) Ordinal.omega.{u1})
+  forall {a : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (OfNat.mk.{succ u1} Ordinal.{u1} 0 (Zero.zero.{succ u1} Ordinal.{u1} Ordinal.hasZero.{u1}))) a) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a Ordinal.omega.{u1}) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a Ordinal.omega.{u1}) Ordinal.omega.{u1})
 but is expected to have type
   forall {a : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (Zero.toOfNat0.{succ u1} Ordinal.{u1} Ordinal.zero.{u1})) a) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a Ordinal.omega.{u1}) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a Ordinal.omega.{u1}) Ordinal.omega.{u1})
 Case conversion may be inaccurate. Consider using '#align ordinal.mul_omega Ordinal.mul_omegaₓ'. -/
@@ -505,7 +541,7 @@ theorem mul_omega {a : Ordinal} (a0 : 0 < a) (ha : a < omega) : a * omega = omeg
 
 /- warning: ordinal.mul_lt_omega_opow -> Ordinal.mul_lt_omega_opow is a dubious translation:
 lean 3 declaration is
-  forall {a : Ordinal.{u1}} {b : Ordinal.{u1}} {c : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (OfNat.mk.{succ u1} Ordinal.{u1} 0 (Zero.zero.{succ u1} Ordinal.{u1} Ordinal.hasZero.{u1}))) c) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} c)) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) b Ordinal.omega.{u1}) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a b) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} c))
+  forall {a : Ordinal.{u1}} {b : Ordinal.{u1}} {c : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (OfNat.mk.{succ u1} Ordinal.{u1} 0 (Zero.zero.{succ u1} Ordinal.{u1} Ordinal.hasZero.{u1}))) c) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} c)) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) b Ordinal.omega.{u1}) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a b) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} c))
 but is expected to have type
   forall {a : Ordinal.{u1}} {b : Ordinal.{u1}} {c : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (Zero.toOfNat0.{succ u1} Ordinal.{u1} Ordinal.zero.{u1})) c) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} c)) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) b Ordinal.omega.{u1}) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a b) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} c))
 Case conversion may be inaccurate. Consider using '#align ordinal.mul_lt_omega_opow Ordinal.mul_lt_omega_opowₓ'. -/
@@ -527,7 +563,7 @@ theorem mul_lt_omega_opow {a b c : Ordinal} (c0 : 0 < c) (ha : a < (omega^c)) (h
 
 /- warning: ordinal.mul_omega_opow_opow -> Ordinal.mul_omega_opow_opow is a dubious translation:
 lean 3 declaration is
-  forall {a : Ordinal.{u1}} {b : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (OfNat.mk.{succ u1} Ordinal.{u1} 0 (Zero.zero.{succ u1} Ordinal.{u1} Ordinal.hasZero.{u1}))) a) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} b))) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} b))) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} b)))
+  forall {a : Ordinal.{u1}} {b : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (OfNat.mk.{succ u1} Ordinal.{u1} 0 (Zero.zero.{succ u1} Ordinal.{u1} Ordinal.hasZero.{u1}))) a) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} b))) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} b))) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} b)))
 but is expected to have type
   forall {a : Ordinal.{u1}} {b : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (Zero.toOfNat0.{succ u1} Ordinal.{u1} Ordinal.zero.{u1})) a) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} b))) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} b))) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} b)))
 Case conversion may be inaccurate. Consider using '#align ordinal.mul_omega_opow_opow Ordinal.mul_omega_opow_opowₓ'. -/
@@ -557,7 +593,7 @@ theorem principal_mul_omega_opow_opow (o : Ordinal) : Principal (· * ·) (omega
 
 /- warning: ordinal.principal_add_of_principal_mul_opow -> Ordinal.principal_add_of_principal_mul_opow is a dubious translation:
 lean 3 declaration is
-  forall {o : Ordinal.{u1}} {b : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (OfNat.mk.{succ u1} Ordinal.{u1} 1 (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1}))) b) -> (Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) b o)) -> (Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) o)
+  forall {o : Ordinal.{u1}} {b : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (OfNat.mk.{succ u1} Ordinal.{u1} 1 (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1}))) b) -> (Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) b o)) -> (Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) o)
 but is expected to have type
   forall {o : Ordinal.{u1}} {b : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (One.toOfNat1.{succ u1} Ordinal.{u1} Ordinal.one.{u1})) b) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4637 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4639 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4637 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4639) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) b o)) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4660 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4662 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4660 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4662) o)
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_add_of_principal_mul_opow Ordinal.principal_add_of_principal_mul_opowₓ'. -/
@@ -570,7 +606,7 @@ theorem principal_add_of_principal_mul_opow {o b : Ordinal} (hb : 1 < b)
 
 /- warning: ordinal.principal_mul_iff_le_two_or_omega_opow_opow -> Ordinal.principal_mul_iff_le_two_or_omega_opow_opow is a dubious translation:
 lean 3 declaration is
-  forall {o : Ordinal.{u1}}, Iff (Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) o) (Or (LE.le.{succ u1} Ordinal.{u1} (Preorder.toLE.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) o (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (OfNat.mk.{succ u1} Ordinal.{u1} 2 (bit0.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1} (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1}))))) (Exists.{succ (succ u1)} Ordinal.{u1} (fun (a : Ordinal.{u1}) => Eq.{succ (succ u1)} Ordinal.{u1} o (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} a)))))
+  forall {o : Ordinal.{u1}}, Iff (Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) o) (Or (LE.le.{succ u1} Ordinal.{u1} (Preorder.toHasLe.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) o (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (OfNat.mk.{succ u1} Ordinal.{u1} 2 (bit0.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1} (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1}))))) (Exists.{succ (succ u1)} Ordinal.{u1} (fun (a : Ordinal.{u1}) => Eq.{succ (succ u1)} Ordinal.{u1} o (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} a)))))
 but is expected to have type
   forall {o : Ordinal.{u1}}, Iff (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4770 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4772 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4770 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4772) o) (Or (LE.le.{succ u1} Ordinal.{u1} (Preorder.toLE.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) o (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (instOfNat.{succ u1} Ordinal.{u1} 2 (AddMonoidWithOne.toNatCast.{succ u1} Ordinal.{u1} Ordinal.addMonoidWithOne.{u1}) (instAtLeastTwoHAddNatInstHAddInstAddNatOfNat (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0)))))) (Exists.{succ (succ u1)} Ordinal.{u1} (fun (a : Ordinal.{u1}) => Eq.{succ (succ u1)} Ordinal.{u1} o (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} a)))))
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_mul_iff_le_two_or_omega_opow_opow Ordinal.principal_mul_iff_le_two_or_omega_opow_opowₓ'. -/
@@ -597,7 +633,7 @@ theorem principal_mul_iff_le_two_or_omega_opow_opow {o : Ordinal} :
 
 /- warning: ordinal.mul_omega_dvd -> Ordinal.mul_omega_dvd is a dubious translation:
 lean 3 declaration is
-  forall {a : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (OfNat.mk.{succ u1} Ordinal.{u1} 0 (Zero.zero.{succ u1} Ordinal.{u1} Ordinal.hasZero.{u1}))) a) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a Ordinal.omega.{u1}) -> (forall {b : Ordinal.{u1}}, (Dvd.Dvd.{succ u1} Ordinal.{u1} (semigroupDvd.{succ u1} Ordinal.{u1} (SemigroupWithZero.toSemigroup.{succ u1} Ordinal.{u1} (MonoidWithZero.toSemigroupWithZero.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))) Ordinal.omega.{u1} b) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a b) b))
+  forall {a : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (OfNat.mk.{succ u1} Ordinal.{u1} 0 (Zero.zero.{succ u1} Ordinal.{u1} Ordinal.hasZero.{u1}))) a) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a Ordinal.omega.{u1}) -> (forall {b : Ordinal.{u1}}, (Dvd.Dvd.{succ u1} Ordinal.{u1} (semigroupDvd.{succ u1} Ordinal.{u1} (SemigroupWithZero.toSemigroup.{succ u1} Ordinal.{u1} (MonoidWithZero.toSemigroupWithZero.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))) Ordinal.omega.{u1} b) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a b) b))
 but is expected to have type
   forall {a : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (Zero.toOfNat0.{succ u1} Ordinal.{u1} Ordinal.zero.{u1})) a) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a Ordinal.omega.{u1}) -> (forall {b : Ordinal.{u1}}, (Dvd.dvd.{succ u1} Ordinal.{u1} (semigroupDvd.{succ u1} Ordinal.{u1} (SemigroupWithZero.toSemigroup.{succ u1} Ordinal.{u1} (MonoidWithZero.toSemigroupWithZero.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))) Ordinal.omega.{u1} b) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a b) b))
 Case conversion may be inaccurate. Consider using '#align ordinal.mul_omega_dvd Ordinal.mul_omega_dvdₓ'. -/
@@ -607,7 +643,7 @@ theorem mul_omega_dvd {a : Ordinal} (a0 : 0 < a) (ha : a < omega) : ∀ {b}, ome
 
 /- warning: ordinal.mul_eq_opow_log_succ -> Ordinal.mul_eq_opow_log_succ is a dubious translation:
 lean 3 declaration is
-  forall {a : Ordinal.{u1}} {b : Ordinal.{u1}}, (Ne.{succ (succ u1)} Ordinal.{u1} a (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (OfNat.mk.{succ u1} Ordinal.{u1} 0 (Zero.zero.{succ u1} Ordinal.{u1} Ordinal.hasZero.{u1})))) -> (Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) b) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (OfNat.mk.{succ u1} Ordinal.{u1} 2 (bit0.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1} (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1})))) b) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a b) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) b (Order.succ.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1}) Ordinal.succOrder.{u1} (Ordinal.log.{u1} b a))))
+  forall {a : Ordinal.{u1}} {b : Ordinal.{u1}}, (Ne.{succ (succ u1)} Ordinal.{u1} a (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (OfNat.mk.{succ u1} Ordinal.{u1} 0 (Zero.zero.{succ u1} Ordinal.{u1} Ordinal.hasZero.{u1})))) -> (Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) b) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (OfNat.mk.{succ u1} Ordinal.{u1} 2 (bit0.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1} (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1})))) b) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a b) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) b (Order.succ.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1}) Ordinal.succOrder.{u1} (Ordinal.log.{u1} b a))))
 but is expected to have type
   forall {a : Ordinal.{u1}} {b : Ordinal.{u1}}, (Ne.{succ (succ u1)} Ordinal.{u1} a (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (Zero.toOfNat0.{succ u1} Ordinal.{u1} Ordinal.zero.{u1}))) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.5010 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.5012 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.5010 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.5012) b) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (instOfNat.{succ u1} Ordinal.{u1} 2 (AddMonoidWithOne.toNatCast.{succ u1} Ordinal.{u1} Ordinal.addMonoidWithOne.{u1}) (instAtLeastTwoHAddNatInstHAddInstAddNatOfNat (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0))))) b) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a b) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) b (Order.succ.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1}) Ordinal.succOrder.{u1} (Ordinal.log.{u1} b a))))
 Case conversion may be inaccurate. Consider using '#align ordinal.mul_eq_opow_log_succ Ordinal.mul_eq_opow_log_succₓ'. -/
@@ -647,7 +683,7 @@ theorem principal_opow_omega : Principal (·^·) omega := fun a b ha hb =>
 
 /- warning: ordinal.opow_omega -> Ordinal.opow_omega is a dubious translation:
 lean 3 declaration is
-  forall {a : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (OfNat.mk.{succ u1} Ordinal.{u1} 1 (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1}))) a) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a Ordinal.omega.{u1}) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) a Ordinal.omega.{u1}) Ordinal.omega.{u1})
+  forall {a : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (OfNat.mk.{succ u1} Ordinal.{u1} 1 (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1}))) a) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toHasLt.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a Ordinal.omega.{u1}) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) a Ordinal.omega.{u1}) Ordinal.omega.{u1})
 but is expected to have type
   forall {a : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (One.toOfNat1.{succ u1} Ordinal.{u1} Ordinal.one.{u1})) a) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a Ordinal.omega.{u1}) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) a Ordinal.omega.{u1}) Ordinal.omega.{u1})
 Case conversion may be inaccurate. Consider using '#align ordinal.opow_omega Ordinal.opow_omegaₓ'. -/
Diff
@@ -129,8 +129,8 @@ def blsub₂ (op : Ordinal → Ordinal → Ordinal) (o : Ordinal) : Ordinal :=
 theorem lt_blsub₂ (op : Ordinal → Ordinal → Ordinal) {o : Ordinal} {a b : Ordinal} (ha : a < o)
     (hb : b < o) : op a b < blsub₂ op o :=
   by
-  convert
-    lt_lsub _ (Prod.mk (enum (· < ·) a (by rwa [type_lt])) (enum (· < ·) b (by rwa [type_lt])))
+  convert lt_lsub _
+      (Prod.mk (enum (· < ·) a (by rwa [type_lt])) (enum (· < ·) b (by rwa [type_lt])))
   simp only [typein_enum]
 #align ordinal.lt_blsub₂ Ordinal.lt_blsub₂
 -/
@@ -166,7 +166,7 @@ theorem unbounded_principal (op : Ordinal → Ordinal → Ordinal) :
 lean 3 declaration is
   Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (OfNat.mk.{succ u1} Ordinal.{u1} 1 (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1})))
 but is expected to have type
-  Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.990 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.992 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.990 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.992) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (One.toOfNat1.{succ u1} Ordinal.{u1} Ordinal.one.{u1}))
+  Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1094 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1096 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1094 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1096) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (One.toOfNat1.{succ u1} Ordinal.{u1} Ordinal.one.{u1}))
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_add_one Ordinal.principal_add_oneₓ'. -/
 theorem principal_add_one : Principal (· + ·) 1 :=
   principal_one_iff.2 <| zero_add 0
@@ -176,7 +176,7 @@ theorem principal_add_one : Principal (· + ·) 1 :=
 lean 3 declaration is
   forall {o : Ordinal.{u1}}, (LE.le.{succ u1} Ordinal.{u1} (Preorder.toLE.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) o (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (OfNat.mk.{succ u1} Ordinal.{u1} 1 (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1})))) -> (Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) o)
 but is expected to have type
-  forall {o : Ordinal.{u1}}, (LE.le.{succ u1} Ordinal.{u1} (Preorder.toLE.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) o (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (One.toOfNat1.{succ u1} Ordinal.{u1} Ordinal.one.{u1}))) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1020 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1022 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1020 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1022) o)
+  forall {o : Ordinal.{u1}}, (LE.le.{succ u1} Ordinal.{u1} (Preorder.toLE.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) o (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (One.toOfNat1.{succ u1} Ordinal.{u1} Ordinal.one.{u1}))) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1124 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1126 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1124 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1126) o)
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_add_of_le_one Ordinal.principal_add_of_le_oneₓ'. -/
 theorem principal_add_of_le_one {o : Ordinal} (ho : o ≤ 1) : Principal (· + ·) o :=
   by
@@ -189,7 +189,7 @@ theorem principal_add_of_le_one {o : Ordinal} (ho : o ≤ 1) : Principal (· + 
 lean 3 declaration is
   forall {o : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (OfNat.mk.{succ u1} Ordinal.{u1} 1 (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1}))) o) -> (Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) o) -> (Ordinal.IsLimit.{u1} o)
 but is expected to have type
-  forall {o : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (One.toOfNat1.{succ u1} Ordinal.{u1} Ordinal.one.{u1})) o) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1062 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1064 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1062 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1064) o) -> (Ordinal.IsLimit.{u1} o)
+  forall {o : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (One.toOfNat1.{succ u1} Ordinal.{u1} Ordinal.one.{u1})) o) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1166 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1168 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1166 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1168) o) -> (Ordinal.IsLimit.{u1} o)
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_add_is_limit Ordinal.principal_add_isLimitₓ'. -/
 theorem principal_add_isLimit {o : Ordinal} (ho₁ : 1 < o) (ho : Principal (· + ·) o) : o.IsLimit :=
   by
@@ -289,7 +289,7 @@ theorem add_omega_opow {a b : Ordinal} (h : a < (omega^b)) : a + (omega^b) = (om
 lean 3 declaration is
   forall (o : Ordinal.{u1}), Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} o)
 but is expected to have type
-  forall (o : Ordinal.{u1}), Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2055 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2057 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2055 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2057) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} o)
+  forall (o : Ordinal.{u1}), Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2159 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2161 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2159 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2161) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} o)
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_add_omega_opow Ordinal.principal_add_omega_opowₓ'. -/
 theorem principal_add_omega_opow (o : Ordinal) : Principal (· + ·) (omega^o) :=
   principal_add_iff_add_left_eq_self.2 fun a => add_omega_opow
@@ -299,7 +299,7 @@ theorem principal_add_omega_opow (o : Ordinal) : Principal (· + ·) (omega^o) :
 lean 3 declaration is
   forall {o : Ordinal.{u1}}, Iff (Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) o) (Or (Eq.{succ (succ u1)} Ordinal.{u1} o (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (OfNat.mk.{succ u1} Ordinal.{u1} 0 (Zero.zero.{succ u1} Ordinal.{u1} Ordinal.hasZero.{u1})))) (Exists.{succ (succ u1)} Ordinal.{u1} (fun (a : Ordinal.{u1}) => Eq.{succ (succ u1)} Ordinal.{u1} o (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} a))))
 but is expected to have type
-  forall {o : Ordinal.{u1}}, Iff (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2090 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2092 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2090 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2092) o) (Or (Eq.{succ (succ u1)} Ordinal.{u1} o (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (Zero.toOfNat0.{succ u1} Ordinal.{u1} Ordinal.zero.{u1}))) (Exists.{succ (succ u1)} Ordinal.{u1} (fun (a : Ordinal.{u1}) => Eq.{succ (succ u1)} Ordinal.{u1} o (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} a))))
+  forall {o : Ordinal.{u1}}, Iff (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2194 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2196 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2194 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2196) o) (Or (Eq.{succ (succ u1)} Ordinal.{u1} o (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (Zero.toOfNat0.{succ u1} Ordinal.{u1} Ordinal.zero.{u1}))) (Exists.{succ (succ u1)} Ordinal.{u1} (fun (a : Ordinal.{u1}) => Eq.{succ (succ u1)} Ordinal.{u1} o (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} a))))
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_add_iff_zero_or_omega_opow Ordinal.principal_add_iff_zero_or_omega_opowₓ'. -/
 /-- The main characterization theorem for additive principal ordinals. -/
 theorem principal_add_iff_zero_or_omega_opow {o : Ordinal} :
@@ -331,7 +331,7 @@ theorem principal_add_iff_zero_or_omega_opow {o : Ordinal} :
 lean 3 declaration is
   forall {a : Ordinal.{u1}}, (Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) a) -> (forall (b : Ordinal.{u1}), Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) a b))
 but is expected to have type
-  forall {a : Ordinal.{u1}}, (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2369 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2371 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2369 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2371) a) -> (forall (b : Ordinal.{u1}), Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2387 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2389 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2387 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2389) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) a b))
+  forall {a : Ordinal.{u1}}, (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2473 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2475 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2473 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2475) a) -> (forall (b : Ordinal.{u1}), Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2491 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2493 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2491 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2493) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) a b))
 Case conversion may be inaccurate. Consider using '#align ordinal.opow_principal_add_of_principal_add Ordinal.opow_principal_add_of_principal_addₓ'. -/
 theorem opow_principal_add_of_principal_add {a} (ha : Principal (· + ·) a) (b : Ordinal) :
     Principal (· + ·) (a^b) :=
@@ -359,7 +359,7 @@ theorem add_absorp {a b c : Ordinal} (h₁ : a < (omega^b)) (h₂ : (omega^b) 
 lean 3 declaration is
   forall (a : Ordinal.{u1}) {b : Ordinal.{u1}}, (Ne.{succ (succ u1)} Ordinal.{u1} b (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (OfNat.mk.{succ u1} Ordinal.{u1} 1 (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1})))) -> (Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) b) -> (Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a b))
 but is expected to have type
-  forall (a : Ordinal.{u1}) {b : Ordinal.{u1}}, (Ne.{succ (succ u1)} Ordinal.{u1} b (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (One.toOfNat1.{succ u1} Ordinal.{u1} Ordinal.one.{u1}))) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2600 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2602 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2600 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2602) b) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2617 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2619 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2617 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2619) (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a b))
+  forall (a : Ordinal.{u1}) {b : Ordinal.{u1}}, (Ne.{succ (succ u1)} Ordinal.{u1} b (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (One.toOfNat1.{succ u1} Ordinal.{u1} Ordinal.one.{u1}))) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2704 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2706 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2704 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2706) b) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2721 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2723 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2721 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.2723) (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a b))
 Case conversion may be inaccurate. Consider using '#align ordinal.mul_principal_add_is_principal_add Ordinal.mul_principal_add_is_principal_addₓ'. -/
 theorem mul_principal_add_is_principal_add (a : Ordinal.{u}) {b : Ordinal.{u}} (hb₁ : b ≠ 1)
     (hb : Principal (· + ·) b) : Principal (· + ·) (a * b) :=
@@ -388,7 +388,7 @@ theorem mul_principal_add_is_principal_add (a : Ordinal.{u}) {b : Ordinal.{u}} (
 lean 3 declaration is
   Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (OfNat.mk.{succ u1} Ordinal.{u1} 1 (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1})))
 but is expected to have type
-  Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3000 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3002 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3000 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3002) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (One.toOfNat1.{succ u1} Ordinal.{u1} Ordinal.one.{u1}))
+  Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3104 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3106 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3104 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3106) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (One.toOfNat1.{succ u1} Ordinal.{u1} Ordinal.one.{u1}))
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_mul_one Ordinal.principal_mul_oneₓ'. -/
 theorem principal_mul_one : Principal (· * ·) 1 :=
   by
@@ -400,7 +400,7 @@ theorem principal_mul_one : Principal (· * ·) 1 :=
 lean 3 declaration is
   Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (OfNat.mk.{succ u1} Ordinal.{u1} 2 (bit0.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1} (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1}))))
 but is expected to have type
-  Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3054 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3056 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3054 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3056) (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (instOfNat.{succ u1} Ordinal.{u1} 2 (AddMonoidWithOne.toNatCast.{succ u1} Ordinal.{u1} Ordinal.addMonoidWithOne.{u1}) (instAtLeastTwoHAddNatInstHAddInstAddNatOfNat (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0)))))
+  Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3158 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3160 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3158 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3160) (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (instOfNat.{succ u1} Ordinal.{u1} 2 (AddMonoidWithOne.toNatCast.{succ u1} Ordinal.{u1} Ordinal.addMonoidWithOne.{u1}) (instAtLeastTwoHAddNatInstHAddInstAddNatOfNat (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0)))))
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_mul_two Ordinal.principal_mul_twoₓ'. -/
 theorem principal_mul_two : Principal (· * ·) 2 := fun a b ha hb =>
   by
@@ -414,7 +414,7 @@ theorem principal_mul_two : Principal (· * ·) 2 := fun a b ha hb =>
 lean 3 declaration is
   forall {o : Ordinal.{u1}}, (LE.le.{succ u1} Ordinal.{u1} (Preorder.toLE.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) o (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (OfNat.mk.{succ u1} Ordinal.{u1} 2 (bit0.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1} (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1}))))) -> (Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) o)
 but is expected to have type
-  forall {o : Ordinal.{u1}}, (LE.le.{succ u1} Ordinal.{u1} (Preorder.toLE.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) o (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (instOfNat.{succ u1} Ordinal.{u1} 2 (AddMonoidWithOne.toNatCast.{succ u1} Ordinal.{u1} Ordinal.addMonoidWithOne.{u1}) (instAtLeastTwoHAddNatInstHAddInstAddNatOfNat (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0)))))) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3164 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3166 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3164 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3166) o)
+  forall {o : Ordinal.{u1}}, (LE.le.{succ u1} Ordinal.{u1} (Preorder.toLE.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) o (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (instOfNat.{succ u1} Ordinal.{u1} 2 (AddMonoidWithOne.toNatCast.{succ u1} Ordinal.{u1} Ordinal.addMonoidWithOne.{u1}) (instAtLeastTwoHAddNatInstHAddInstAddNatOfNat (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0)))))) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3320 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3322 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3320 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3322) o)
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_mul_of_le_two Ordinal.principal_mul_of_le_twoₓ'. -/
 theorem principal_mul_of_le_two {o : Ordinal} (ho : o ≤ 2) : Principal (· * ·) o :=
   by
@@ -432,7 +432,7 @@ theorem principal_mul_of_le_two {o : Ordinal} (ho : o ≤ 2) : Principal (· * 
 lean 3 declaration is
   forall {o : Ordinal.{u1}}, (Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) o) -> (Ne.{succ (succ u1)} Ordinal.{u1} o (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (OfNat.mk.{succ u1} Ordinal.{u1} 2 (bit0.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1} (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1}))))) -> (Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) o)
 but is expected to have type
-  forall {o : Ordinal.{u1}}, (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3299 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3301 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3299 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3301) o) -> (Ne.{succ (succ u1)} Ordinal.{u1} o (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (instOfNat.{succ u1} Ordinal.{u1} 2 (AddMonoidWithOne.toNatCast.{succ u1} Ordinal.{u1} Ordinal.addMonoidWithOne.{u1}) (instAtLeastTwoHAddNatInstHAddInstAddNatOfNat (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0)))))) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3321 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3323 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3321 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3323) o)
+  forall {o : Ordinal.{u1}}, (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3455 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3457 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3455 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3457) o) -> (Ne.{succ (succ u1)} Ordinal.{u1} o (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (instOfNat.{succ u1} Ordinal.{u1} 2 (AddMonoidWithOne.toNatCast.{succ u1} Ordinal.{u1} Ordinal.addMonoidWithOne.{u1}) (instAtLeastTwoHAddNatInstHAddInstAddNatOfNat (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0)))))) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3477 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3479 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3477 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3479) o)
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_add_of_principal_mul Ordinal.principal_add_of_principal_mulₓ'. -/
 theorem principal_add_of_principal_mul {o : Ordinal} (ho : Principal (· * ·) o) (ho₂ : o ≠ 2) :
     Principal (· + ·) o := by
@@ -449,7 +449,7 @@ theorem principal_add_of_principal_mul {o : Ordinal} (ho : Principal (· * ·) o
 lean 3 declaration is
   forall {o : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (OfNat.mk.{succ u1} Ordinal.{u1} 2 (bit0.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1} (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1})))) o) -> (Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) o) -> (Ordinal.IsLimit.{u1} o)
 but is expected to have type
-  forall {o : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (instOfNat.{succ u1} Ordinal.{u1} 2 (AddMonoidWithOne.toNatCast.{succ u1} Ordinal.{u1} Ordinal.addMonoidWithOne.{u1}) (instAtLeastTwoHAddNatInstHAddInstAddNatOfNat (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0))))) o) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3483 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3485 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3483 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3485) o) -> (Ordinal.IsLimit.{u1} o)
+  forall {o : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (instOfNat.{succ u1} Ordinal.{u1} 2 (AddMonoidWithOne.toNatCast.{succ u1} Ordinal.{u1} Ordinal.addMonoidWithOne.{u1}) (instAtLeastTwoHAddNatInstHAddInstAddNatOfNat (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0))))) o) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3639 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3641 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3639 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3641) o) -> (Ordinal.IsLimit.{u1} o)
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_mul_is_limit Ordinal.principal_mul_isLimitₓ'. -/
 theorem principal_mul_isLimit {o : Ordinal.{u}} (ho₂ : 2 < o) (ho : Principal (· * ·) o) :
     o.IsLimit :=
@@ -460,7 +460,7 @@ theorem principal_mul_isLimit {o : Ordinal.{u}} (ho₂ : 2 < o) (ho : Principal
 lean 3 declaration is
   forall {o : Ordinal.{u1}}, Iff (Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) o) (forall (a : Ordinal.{u1}), (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (OfNat.mk.{succ u1} Ordinal.{u1} 0 (Zero.zero.{succ u1} Ordinal.{u1} Ordinal.hasZero.{u1}))) a) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a o) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a o) o))
 but is expected to have type
-  forall {o : Ordinal.{u1}}, Iff (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3532 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3534 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3532 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3534) o) (forall (a : Ordinal.{u1}), (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (Zero.toOfNat0.{succ u1} Ordinal.{u1} Ordinal.zero.{u1})) a) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a o) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a o) o))
+  forall {o : Ordinal.{u1}}, Iff (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3688 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3690 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3688 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3690) o) (forall (a : Ordinal.{u1}), (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (Zero.toOfNat0.{succ u1} Ordinal.{u1} Ordinal.zero.{u1})) a) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a o) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a o) o))
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_mul_iff_mul_left_eq Ordinal.principal_mul_iff_mul_left_eqₓ'. -/
 theorem principal_mul_iff_mul_left_eq {o : Ordinal} :
     Principal (· * ·) o ↔ ∀ a, 0 < a → a < o → a * o = o :=
@@ -484,7 +484,7 @@ theorem principal_mul_iff_mul_left_eq {o : Ordinal} :
 lean 3 declaration is
   Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) Ordinal.omega.{u1}
 but is expected to have type
-  Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3849 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3851 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3849 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3851) Ordinal.omega.{u1}
+  Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4047 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4049 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4047 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4049) Ordinal.omega.{u1}
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_mul_omega Ordinal.principal_mul_omegaₓ'. -/
 theorem principal_mul_omega : Principal (· * ·) omega := fun a b ha hb =>
   match a, b, lt_omega.1 ha, lt_omega.1 hb with
@@ -549,7 +549,7 @@ theorem mul_omega_opow_opow {a b : Ordinal} (a0 : 0 < a) (h : a < (omega^omega^b
 lean 3 declaration is
   forall (o : Ordinal.{u1}), Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} o))
 but is expected to have type
-  forall (o : Ordinal.{u1}), Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4399 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4401 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4399 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4401) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} o))
+  forall (o : Ordinal.{u1}), Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4597 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4599 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4597 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4599) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} o))
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_mul_omega_opow_opow Ordinal.principal_mul_omega_opow_opowₓ'. -/
 theorem principal_mul_omega_opow_opow (o : Ordinal) : Principal (· * ·) (omega^omega^o) :=
   principal_mul_iff_mul_left_eq.2 fun a => mul_omega_opow_opow
@@ -559,7 +559,7 @@ theorem principal_mul_omega_opow_opow (o : Ordinal) : Principal (· * ·) (omega
 lean 3 declaration is
   forall {o : Ordinal.{u1}} {b : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (OfNat.mk.{succ u1} Ordinal.{u1} 1 (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1}))) b) -> (Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) b o)) -> (Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) o)
 but is expected to have type
-  forall {o : Ordinal.{u1}} {b : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (One.toOfNat1.{succ u1} Ordinal.{u1} Ordinal.one.{u1})) b) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4439 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4441 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4439 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4441) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) b o)) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4462 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4464 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4462 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4464) o)
+  forall {o : Ordinal.{u1}} {b : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (One.toOfNat1.{succ u1} Ordinal.{u1} Ordinal.one.{u1})) b) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4637 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4639 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4637 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4639) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) b o)) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4660 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4662 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4660 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4662) o)
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_add_of_principal_mul_opow Ordinal.principal_add_of_principal_mul_opowₓ'. -/
 theorem principal_add_of_principal_mul_opow {o b : Ordinal} (hb : 1 < b)
     (ho : Principal (· * ·) (b^o)) : Principal (· + ·) o := fun x y hx hy =>
@@ -572,7 +572,7 @@ theorem principal_add_of_principal_mul_opow {o b : Ordinal} (hb : 1 < b)
 lean 3 declaration is
   forall {o : Ordinal.{u1}}, Iff (Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) o) (Or (LE.le.{succ u1} Ordinal.{u1} (Preorder.toLE.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) o (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (OfNat.mk.{succ u1} Ordinal.{u1} 2 (bit0.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1} (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1}))))) (Exists.{succ (succ u1)} Ordinal.{u1} (fun (a : Ordinal.{u1}) => Eq.{succ (succ u1)} Ordinal.{u1} o (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} a)))))
 but is expected to have type
-  forall {o : Ordinal.{u1}}, Iff (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4572 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4574 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4572 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4574) o) (Or (LE.le.{succ u1} Ordinal.{u1} (Preorder.toLE.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) o (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (instOfNat.{succ u1} Ordinal.{u1} 2 (AddMonoidWithOne.toNatCast.{succ u1} Ordinal.{u1} Ordinal.addMonoidWithOne.{u1}) (instAtLeastTwoHAddNatInstHAddInstAddNatOfNat (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0)))))) (Exists.{succ (succ u1)} Ordinal.{u1} (fun (a : Ordinal.{u1}) => Eq.{succ (succ u1)} Ordinal.{u1} o (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} a)))))
+  forall {o : Ordinal.{u1}}, Iff (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4770 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4772 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4770 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4772) o) (Or (LE.le.{succ u1} Ordinal.{u1} (Preorder.toLE.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) o (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (instOfNat.{succ u1} Ordinal.{u1} 2 (AddMonoidWithOne.toNatCast.{succ u1} Ordinal.{u1} Ordinal.addMonoidWithOne.{u1}) (instAtLeastTwoHAddNatInstHAddInstAddNatOfNat (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0)))))) (Exists.{succ (succ u1)} Ordinal.{u1} (fun (a : Ordinal.{u1}) => Eq.{succ (succ u1)} Ordinal.{u1} o (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) Ordinal.omega.{u1} a)))))
 Case conversion may be inaccurate. Consider using '#align ordinal.principal_mul_iff_le_two_or_omega_opow_opow Ordinal.principal_mul_iff_le_two_or_omega_opow_opowₓ'. -/
 /-- The main characterization theorem for multiplicative principal ordinals. -/
 theorem principal_mul_iff_le_two_or_omega_opow_opow {o : Ordinal} :
@@ -609,7 +609,7 @@ theorem mul_omega_dvd {a : Ordinal} (a0 : 0 < a) (ha : a < omega) : ∀ {b}, ome
 lean 3 declaration is
   forall {a : Ordinal.{u1}} {b : Ordinal.{u1}}, (Ne.{succ (succ u1)} Ordinal.{u1} a (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (OfNat.mk.{succ u1} Ordinal.{u1} 0 (Zero.zero.{succ u1} Ordinal.{u1} Ordinal.hasZero.{u1})))) -> (Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) b) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (OfNat.mk.{succ u1} Ordinal.{u1} 2 (bit0.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1} (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1})))) b) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a b) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) b (Order.succ.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1}) Ordinal.succOrder.{u1} (Ordinal.log.{u1} b a))))
 but is expected to have type
-  forall {a : Ordinal.{u1}} {b : Ordinal.{u1}}, (Ne.{succ (succ u1)} Ordinal.{u1} a (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (Zero.toOfNat0.{succ u1} Ordinal.{u1} Ordinal.zero.{u1}))) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4812 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4814 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4812 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.4814) b) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (instOfNat.{succ u1} Ordinal.{u1} 2 (AddMonoidWithOne.toNatCast.{succ u1} Ordinal.{u1} Ordinal.addMonoidWithOne.{u1}) (instAtLeastTwoHAddNatInstHAddInstAddNatOfNat (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0))))) b) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a b) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) b (Order.succ.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1}) Ordinal.succOrder.{u1} (Ordinal.log.{u1} b a))))
+  forall {a : Ordinal.{u1}} {b : Ordinal.{u1}}, (Ne.{succ (succ u1)} Ordinal.{u1} a (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (Zero.toOfNat0.{succ u1} Ordinal.{u1} Ordinal.zero.{u1}))) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.5010 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.5012 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.5010 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.5012) b) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 2 (instOfNat.{succ u1} Ordinal.{u1} 2 (AddMonoidWithOne.toNatCast.{succ u1} Ordinal.{u1} Ordinal.addMonoidWithOne.{u1}) (instAtLeastTwoHAddNatInstHAddInstAddNatOfNat (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0))))) b) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a b) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.pow.{u1}) b (Order.succ.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1}) Ordinal.succOrder.{u1} (Ordinal.log.{u1} b a))))
 Case conversion may be inaccurate. Consider using '#align ordinal.mul_eq_opow_log_succ Ordinal.mul_eq_opow_log_succₓ'. -/
 theorem mul_eq_opow_log_succ {a b : Ordinal.{u}} (ha : a ≠ 0) (hb : Principal (· * ·) b)
     (hb₂ : 2 < b) : a * b = (b^succ (log b a)) :=
Diff
@@ -323,7 +323,7 @@ theorem principal_add_iff_zero_or_omega_opow {o : Ordinal} :
     suffices e : (omega^log omega o) * ↑n + o = o
     · simpa only [e] using le_add_right ((omega^log omega o) * ↑n) o
     induction' n with n IH
-    · simp only [Nat.cast_zero, mul_zero, zero_add]
+    · simp only [Nat.cast_zero, MulZeroClass.mul_zero, zero_add]
     simp only [Nat.cast_succ, mul_add_one, add_assoc, this, IH]
 #align ordinal.principal_add_iff_zero_or_omega_opow Ordinal.principal_add_iff_zero_or_omega_opow
 
@@ -365,10 +365,10 @@ theorem mul_principal_add_is_principal_add (a : Ordinal.{u}) {b : Ordinal.{u}} (
     (hb : Principal (· + ·) b) : Principal (· + ·) (a * b) :=
   by
   rcases eq_zero_or_pos a with (rfl | ha)
-  · rw [zero_mul]
+  · rw [MulZeroClass.zero_mul]
     exact principal_zero
   · rcases eq_zero_or_pos b with (rfl | hb₁')
-    · rw [mul_zero]
+    · rw [MulZeroClass.mul_zero]
       exact principal_zero
     · rw [← succ_le_iff, succ_zero] at hb₁'
       intro c d hc hd
@@ -393,7 +393,7 @@ Case conversion may be inaccurate. Consider using '#align ordinal.principal_mul_
 theorem principal_mul_one : Principal (· * ·) 1 :=
   by
   rw [principal_one_iff]
-  exact zero_mul _
+  exact MulZeroClass.zero_mul _
 #align ordinal.principal_mul_one Ordinal.principal_mul_one
 
 /- warning: ordinal.principal_mul_two -> Ordinal.principal_mul_two is a dubious translation:
@@ -474,7 +474,7 @@ theorem principal_mul_iff_mul_left_eq {o : Ordinal} :
       · rwa [← succ_le_iff, succ_zero] at ha₀
     · exact op_eq_self_of_principal hao (mul_is_normal ha₀) h (principal_mul_is_limit ho h)
   · rcases eq_or_ne a 0 with (rfl | ha)
-    · rwa [zero_mul]
+    · rwa [MulZeroClass.zero_mul]
     rw [← Ordinal.pos_iff_ne_zero] at ha
     rw [← h a ha hao]
     exact (mul_is_normal ha).StrictMono hbo
Diff
@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Violeta Hernández Palacios
 
 ! This file was ported from Lean 3 source module set_theory.ordinal.principal
-! leanprover-community/mathlib commit 9b2660e1b25419042c8da10bf411aa3c67f14383
+! leanprover-community/mathlib commit 3dadefa3f544b1db6214777fe47910739b54c66a
 ! Please do not edit these lines, except to modify the commit id
 ! if you have ported upstream changes.
 -/
@@ -13,6 +13,9 @@ import Mathbin.SetTheory.Ordinal.FixedPoint
 /-!
 ### Principal ordinals
 
+> THIS FILE IS SYNCHRONIZED WITH MATHLIB4.
+> Any changes to this file require a corresponding PR to mathlib4.
+
 We define principal or indecomposable ordinals, and we prove the standard properties about them.
 
 ### Main definitions and results
Diff
@@ -44,6 +44,7 @@ local infixr:0 "^" => @pow Ordinal Ordinal Ordinal.hasPow
 /-! ### Principal ordinals -/
 
 
+#print Ordinal.Principal /-
 /-- An ordinal `o` is said to be principal or indecomposable under an operation when the set of
 ordinals less than it is closed under that operation. In standard mathematical usage, this term is
 almost exclusively used for additive and multiplicative principal ordinals.
@@ -52,16 +53,27 @@ For simplicity, we break usual convention and regard 0 as principal. -/
 def Principal (op : Ordinal → Ordinal → Ordinal) (o : Ordinal) : Prop :=
   ∀ ⦃a b⦄, a < o → b < o → op a b < o
 #align ordinal.principal Ordinal.Principal
+-/
 
+#print Ordinal.principal_iff_principal_swap /-
 theorem principal_iff_principal_swap {op : Ordinal → Ordinal → Ordinal} {o : Ordinal} :
     Principal op o ↔ Principal (Function.swap op) o := by
   constructor <;> exact fun h a b ha hb => h hb ha
 #align ordinal.principal_iff_principal_swap Ordinal.principal_iff_principal_swap
+-/
 
+#print Ordinal.principal_zero /-
 theorem principal_zero {op : Ordinal → Ordinal → Ordinal} : Principal op 0 := fun a _ h =>
   (Ordinal.not_lt_zero a h).elim
 #align ordinal.principal_zero Ordinal.principal_zero
+-/
 
+/- warning: ordinal.principal_one_iff -> Ordinal.principal_one_iff is a dubious translation:
+lean 3 declaration is
+  forall {op : Ordinal.{u1} -> Ordinal.{u1} -> Ordinal.{u1}}, Iff (Ordinal.Principal.{u1} op (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (OfNat.mk.{succ u1} Ordinal.{u1} 1 (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1})))) (Eq.{succ (succ u1)} Ordinal.{u1} (op (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (OfNat.mk.{succ u1} Ordinal.{u1} 0 (Zero.zero.{succ u1} Ordinal.{u1} Ordinal.hasZero.{u1}))) (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (OfNat.mk.{succ u1} Ordinal.{u1} 0 (Zero.zero.{succ u1} Ordinal.{u1} Ordinal.hasZero.{u1})))) (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (OfNat.mk.{succ u1} Ordinal.{u1} 0 (Zero.zero.{succ u1} Ordinal.{u1} Ordinal.hasZero.{u1}))))
+but is expected to have type
+  forall {op : Ordinal.{u1} -> Ordinal.{u1} -> Ordinal.{u1}}, Iff (Ordinal.Principal.{u1} op (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (One.toOfNat1.{succ u1} Ordinal.{u1} Ordinal.one.{u1}))) (Eq.{succ (succ u1)} Ordinal.{u1} (op (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (Zero.toOfNat0.{succ u1} Ordinal.{u1} Ordinal.zero.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (Zero.toOfNat0.{succ u1} Ordinal.{u1} Ordinal.zero.{u1}))) (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (Zero.toOfNat0.{succ u1} Ordinal.{u1} Ordinal.zero.{u1})))
+Case conversion may be inaccurate. Consider using '#align ordinal.principal_one_iff Ordinal.principal_one_iffₓ'. -/
 @[simp]
 theorem principal_one_iff {op : Ordinal → Ordinal → Ordinal} : Principal op 1 ↔ op 0 0 = 0 :=
   by
@@ -71,6 +83,7 @@ theorem principal_one_iff {op : Ordinal → Ordinal → Ordinal} : Principal op
   · rwa [lt_one_iff_zero, ha, hb] at *
 #align ordinal.principal_one_iff Ordinal.principal_one_iff
 
+#print Ordinal.Principal.iterate_lt /-
 theorem Principal.iterate_lt {op : Ordinal → Ordinal → Ordinal} {a o : Ordinal} (hao : a < o)
     (ho : Principal op o) (n : ℕ) : (op a^[n]) a < o :=
   by
@@ -79,7 +92,9 @@ theorem Principal.iterate_lt {op : Ordinal → Ordinal → Ordinal} {a o : Ordin
   · rw [Function.iterate_succ']
     exact ho hao hn
 #align ordinal.principal.iterate_lt Ordinal.Principal.iterate_lt
+-/
 
+#print Ordinal.op_eq_self_of_principal /-
 theorem op_eq_self_of_principal {op : Ordinal → Ordinal → Ordinal} {a o : Ordinal.{u}} (hao : a < o)
     (H : IsNormal (op a)) (ho : Principal op o) (ho' : IsLimit o) : op a o = o :=
   by
@@ -87,21 +102,27 @@ theorem op_eq_self_of_principal {op : Ordinal → Ordinal → Ordinal} {a o : Or
   rw [← IsNormal.bsup_eq.{u, u} H ho', bsup_le_iff]
   exact fun b hbo => (ho hao hbo).le
 #align ordinal.op_eq_self_of_principal Ordinal.op_eq_self_of_principal
+-/
 
+#print Ordinal.nfp_le_of_principal /-
 theorem nfp_le_of_principal {op : Ordinal → Ordinal → Ordinal} {a o : Ordinal} (hao : a < o)
     (ho : Principal op o) : nfp (op a) a ≤ o :=
   nfp_le fun n => (ho.iterate_lt hao n).le
 #align ordinal.nfp_le_of_principal Ordinal.nfp_le_of_principal
+-/
 
 /-! ### Principal ordinals are unbounded -/
 
 
+#print Ordinal.blsub₂ /-
 /-- The least strict upper bound of `op` applied to all pairs of ordinals less than `o`. This is
 essentially a two-argument version of `ordinal.blsub`. -/
 def blsub₂ (op : Ordinal → Ordinal → Ordinal) (o : Ordinal) : Ordinal :=
   lsub fun x : o.out.α × o.out.α => op (typein (· < ·) x.1) (typein (· < ·) x.2)
 #align ordinal.blsub₂ Ordinal.blsub₂
+-/
 
+#print Ordinal.lt_blsub₂ /-
 theorem lt_blsub₂ (op : Ordinal → Ordinal → Ordinal) {o : Ordinal} {a b : Ordinal} (ha : a < o)
     (hb : b < o) : op a b < blsub₂ op o :=
   by
@@ -109,7 +130,9 @@ theorem lt_blsub₂ (op : Ordinal → Ordinal → Ordinal) {o : Ordinal} {a b :
     lt_lsub _ (Prod.mk (enum (· < ·) a (by rwa [type_lt])) (enum (· < ·) b (by rwa [type_lt])))
   simp only [typein_enum]
 #align ordinal.lt_blsub₂ Ordinal.lt_blsub₂
+-/
 
+#print Ordinal.principal_nfp_blsub₂ /-
 theorem principal_nfp_blsub₂ (op : Ordinal → Ordinal → Ordinal) (o : Ordinal) :
     Principal op (nfp (blsub₂.{u, u} op) o) := fun a b ha hb =>
   by
@@ -124,19 +147,34 @@ theorem principal_nfp_blsub₂ (op : Ordinal → Ordinal → Ordinal) (o : Ordin
     rw [Function.iterate_succ']
     exact lt_blsub₂ op hm (hn.trans_le h)
 #align ordinal.principal_nfp_blsub₂ Ordinal.principal_nfp_blsub₂
+-/
 
+#print Ordinal.unbounded_principal /-
 theorem unbounded_principal (op : Ordinal → Ordinal → Ordinal) :
     Set.Unbounded (· < ·) { o | Principal op o } := fun o =>
   ⟨_, principal_nfp_blsub₂ op o, (le_nfp _ o).not_lt⟩
 #align ordinal.unbounded_principal Ordinal.unbounded_principal
+-/
 
 /-! #### Additive principal ordinals -/
 
 
+/- warning: ordinal.principal_add_one -> Ordinal.principal_add_one is a dubious translation:
+lean 3 declaration is
+  Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (OfNat.mk.{succ u1} Ordinal.{u1} 1 (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1})))
+but is expected to have type
+  Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.990 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.992 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.990 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.992) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (One.toOfNat1.{succ u1} Ordinal.{u1} Ordinal.one.{u1}))
+Case conversion may be inaccurate. Consider using '#align ordinal.principal_add_one Ordinal.principal_add_oneₓ'. -/
 theorem principal_add_one : Principal (· + ·) 1 :=
   principal_one_iff.2 <| zero_add 0
 #align ordinal.principal_add_one Ordinal.principal_add_one
 
+/- warning: ordinal.principal_add_of_le_one -> Ordinal.principal_add_of_le_one is a dubious translation:
+lean 3 declaration is
+  forall {o : Ordinal.{u1}}, (LE.le.{succ u1} Ordinal.{u1} (Preorder.toLE.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) o (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (OfNat.mk.{succ u1} Ordinal.{u1} 1 (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1})))) -> (Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) o)
+but is expected to have type
+  forall {o : Ordinal.{u1}}, (LE.le.{succ u1} Ordinal.{u1} (Preorder.toLE.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) o (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (One.toOfNat1.{succ u1} Ordinal.{u1} Ordinal.one.{u1}))) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1020 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1022 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1020 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1022) o)
+Case conversion may be inaccurate. Consider using '#align ordinal.principal_add_of_le_one Ordinal.principal_add_of_le_oneₓ'. -/
 theorem principal_add_of_le_one {o : Ordinal} (ho : o ≤ 1) : Principal (· + ·) o :=
   by
   rcases le_one_iff.1 ho with (rfl | rfl)
@@ -144,6 +182,12 @@ theorem principal_add_of_le_one {o : Ordinal} (ho : o ≤ 1) : Principal (· + 
   · exact principal_add_one
 #align ordinal.principal_add_of_le_one Ordinal.principal_add_of_le_one
 
+/- warning: ordinal.principal_add_is_limit -> Ordinal.principal_add_isLimit is a dubious translation:
+lean 3 declaration is
+  forall {o : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (OfNat.mk.{succ u1} Ordinal.{u1} 1 (One.one.{succ u1} Ordinal.{u1} Ordinal.hasOne.{u1}))) o) -> (Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) o) -> (Ordinal.IsLimit.{u1} o)
+but is expected to have type
+  forall {o : Ordinal.{u1}}, (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (One.toOfNat1.{succ u1} Ordinal.{u1} Ordinal.one.{u1})) o) -> (Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1062 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1064 : Ordinal.{u1}) => HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.add.{u1}) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1062 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.1064) o) -> (Ordinal.IsLimit.{u1} o)
+Case conversion may be inaccurate. Consider using '#align ordinal.principal_add_is_limit Ordinal.principal_add_isLimitₓ'. -/
 theorem principal_add_isLimit {o : Ordinal} (ho₁ : 1 < o) (ho : Principal (· + ·) o) : o.IsLimit :=
   by
   refine' ⟨fun ho₀ => _, fun a hao => _⟩
@@ -156,6 +200,7 @@ theorem principal_add_isLimit {o : Ordinal} (ho₁ : 1 < o) (ho : Principal (·
       rwa [← add_one_eq_succ, add_le_add_iff_left, one_le_iff_ne_zero]
 #align ordinal.principal_add_is_limit Ordinal.principal_add_isLimit
 
+#print Ordinal.principal_add_iff_add_left_eq_self /-
 theorem principal_add_iff_add_left_eq_self {o : Ordinal} :
     Principal (· + ·) o ↔ ∀ a < o, a + o = o :=
   by
@@ -169,7 +214,9 @@ theorem principal_add_iff_add_left_eq_self {o : Ordinal} :
   · rw [← h a hao]
     exact (add_is_normal a).StrictMono hbo
 #align ordinal.principal_add_iff_add_left_eq_self Ordinal.principal_add_iff_add_left_eq_self
+-/
 
+#print Ordinal.exists_lt_add_of_not_principal_add /-
 theorem exists_lt_add_of_not_principal_add {a} (ha : ¬Principal (· + ·) a) :
     ∃ (b c : _)(hb : b < a)(hc : c < a), b + c = a :=
   by
@@ -181,7 +228,9 @@ theorem exists_lt_add_of_not_principal_add {a} (ha : ¬Principal (· + ·) a) :
   rw [← sub_le, hab] at H
   exact H.not_lt hc
 #align ordinal.exists_lt_add_of_not_principal_add Ordinal.exists_lt_add_of_not_principal_add
+-/
 
+#print Ordinal.principal_add_iff_add_lt_ne_self /-
 theorem principal_add_iff_add_lt_ne_self {a} :
     Principal (· + ·) a ↔ ∀ ⦃b c⦄, b < a → c < a → b + c ≠ a :=
   ⟨fun ha b c hb hc => (ha hb hc).Ne, fun H =>
@@ -190,7 +239,9 @@ theorem principal_add_iff_add_lt_ne_self {a} :
     rcases exists_lt_add_of_not_principal_add ha with ⟨b, c, hb, hc, rfl⟩
     exact (H hb hc).irrefl⟩
 #align ordinal.principal_add_iff_add_lt_ne_self Ordinal.principal_add_iff_add_lt_ne_self
+-/
 
+#print Ordinal.add_omega /-
 theorem add_omega {a : Ordinal} (h : a < omega) : a + omega = omega :=
   by
   rcases lt_omega.1 h with ⟨n, rfl⟩
@@ -198,11 +249,20 @@ theorem add_omega {a : Ordinal} (h : a < omega) : a + omega = omega :=
   · rw [Nat.cast_zero, zero_add]
   · rwa [Nat.cast_succ, add_assoc, one_add_of_omega_le (le_refl _)]
 #align ordinal.add_omega Ordinal.add_omega
+-/
 
+#print Ordinal.principal_add_omega /-
 theorem principal_add_omega : Principal (· + ·) omega :=
   principal_add_iff_add_left_eq_self.2 fun a => add_omega
 #align ordinal.principal_add_omega Ordinal.principal_add_omega
+-/
 
+/- warning: ordinal.add_omega_opow -> Ordinal.add_omega_opow is a dubious translation:
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+Case conversion may be inaccurate. Consider using '#align ordinal.add_omega_opow Ordinal.add_omega_opowₓ'. -/
 theorem add_omega_opow {a b : Ordinal} (h : a < (omega^b)) : a + (omega^b) = (omega^b) :=
   by
   refine' le_antisymm _ (le_add_left _ _)
@@ -222,10 +282,22 @@ theorem add_omega_opow {a b : Ordinal} (h : a < (omega^b)) : a + (omega^b) = (om
             (opow_le_opow_right omega_pos <| le_of_lt <| max_lt xb yb))
 #align ordinal.add_omega_opow Ordinal.add_omega_opow
 
+/- warning: ordinal.principal_add_omega_opow -> Ordinal.principal_add_omega_opow is a dubious translation:
+lean 3 declaration is
+  forall (o : Ordinal.{u1}), Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} o)
+but is expected to have type
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+Case conversion may be inaccurate. Consider using '#align ordinal.principal_add_omega_opow Ordinal.principal_add_omega_opowₓ'. -/
 theorem principal_add_omega_opow (o : Ordinal) : Principal (· + ·) (omega^o) :=
   principal_add_iff_add_left_eq_self.2 fun a => add_omega_opow
 #align ordinal.principal_add_omega_opow Ordinal.principal_add_omega_opow
 
+/- warning: ordinal.principal_add_iff_zero_or_omega_opow -> Ordinal.principal_add_iff_zero_or_omega_opow is a dubious translation:
+lean 3 declaration is
+  forall {o : Ordinal.{u1}}, Iff (Ordinal.Principal.{u1} (HAdd.hAdd.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHAdd.{succ u1} Ordinal.{u1} Ordinal.hasAdd.{u1})) o) (Or (Eq.{succ (succ u1)} Ordinal.{u1} o (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (OfNat.mk.{succ u1} Ordinal.{u1} 0 (Zero.zero.{succ u1} Ordinal.{u1} Ordinal.hasZero.{u1})))) (Exists.{succ (succ u1)} Ordinal.{u1} (fun (a : Ordinal.{u1}) => Eq.{succ (succ u1)} Ordinal.{u1} o (HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) Ordinal.omega.{u1} a))))
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+Case conversion may be inaccurate. Consider using '#align ordinal.principal_add_iff_zero_or_omega_opow Ordinal.principal_add_iff_zero_or_omega_opowₓ'. -/
 /-- The main characterization theorem for additive principal ordinals. -/
 theorem principal_add_iff_zero_or_omega_opow {o : Ordinal} :
     Principal (· + ·) o ↔ o = 0 ∨ ∃ a, o = (omega^a) :=
@@ -252,6 +324,12 @@ theorem principal_add_iff_zero_or_omega_opow {o : Ordinal} :
     simp only [Nat.cast_succ, mul_add_one, add_assoc, this, IH]
 #align ordinal.principal_add_iff_zero_or_omega_opow Ordinal.principal_add_iff_zero_or_omega_opow
 
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+Case conversion may be inaccurate. Consider using '#align ordinal.opow_principal_add_of_principal_add Ordinal.opow_principal_add_of_principal_addₓ'. -/
 theorem opow_principal_add_of_principal_add {a} (ha : Principal (· + ·) a) (b : Ordinal) :
     Principal (· + ·) (a^b) :=
   by
@@ -264,10 +342,22 @@ theorem opow_principal_add_of_principal_add {a} (ha : Principal (· + ·) a) (b
     exact principal_add_omega_opow _
 #align ordinal.opow_principal_add_of_principal_add Ordinal.opow_principal_add_of_principal_add
 
+/- warning: ordinal.add_absorp -> Ordinal.add_absorp is a dubious translation:
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+but is expected to have type
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+Case conversion may be inaccurate. Consider using '#align ordinal.add_absorp Ordinal.add_absorpₓ'. -/
 theorem add_absorp {a b c : Ordinal} (h₁ : a < (omega^b)) (h₂ : (omega^b) ≤ c) : a + c = c := by
   rw [← Ordinal.add_sub_cancel_of_le h₂, ← add_assoc, add_omega_opow h₁]
 #align ordinal.add_absorp Ordinal.add_absorp
 
+/- warning: ordinal.mul_principal_add_is_principal_add -> Ordinal.mul_principal_add_is_principal_add is a dubious translation:
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+but is expected to have type
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+Case conversion may be inaccurate. Consider using '#align ordinal.mul_principal_add_is_principal_add Ordinal.mul_principal_add_is_principal_addₓ'. -/
 theorem mul_principal_add_is_principal_add (a : Ordinal.{u}) {b : Ordinal.{u}} (hb₁ : b ≠ 1)
     (hb : Principal (· + ·) b) : Principal (· + ·) (a * b) :=
   by
@@ -291,12 +381,24 @@ theorem mul_principal_add_is_principal_add (a : Ordinal.{u}) {b : Ordinal.{u}} (
 /-! #### Multiplicative principal ordinals -/
 
 
+/- warning: ordinal.principal_mul_one -> Ordinal.principal_mul_one is a dubious translation:
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+but is expected to have type
+  Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3000 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3002 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3000 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3002) (OfNat.ofNat.{succ u1} Ordinal.{u1} 1 (One.toOfNat1.{succ u1} Ordinal.{u1} Ordinal.one.{u1}))
+Case conversion may be inaccurate. Consider using '#align ordinal.principal_mul_one Ordinal.principal_mul_oneₓ'. -/
 theorem principal_mul_one : Principal (· * ·) 1 :=
   by
   rw [principal_one_iff]
   exact zero_mul _
 #align ordinal.principal_mul_one Ordinal.principal_mul_one
 
+/- warning: ordinal.principal_mul_two -> Ordinal.principal_mul_two is a dubious translation:
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+but is expected to have type
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+Case conversion may be inaccurate. Consider using '#align ordinal.principal_mul_two Ordinal.principal_mul_twoₓ'. -/
 theorem principal_mul_two : Principal (· * ·) 2 := fun a b ha hb =>
   by
   have h₂ : succ (1 : Ordinal) = 2 := rfl
@@ -305,6 +407,12 @@ theorem principal_mul_two : Principal (· * ·) 2 := fun a b ha hb =>
   exact (mul_one 1).symm
 #align ordinal.principal_mul_two Ordinal.principal_mul_two
 
+/- warning: ordinal.principal_mul_of_le_two -> Ordinal.principal_mul_of_le_two is a dubious translation:
+lean 3 declaration is
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+Case conversion may be inaccurate. Consider using '#align ordinal.principal_mul_of_le_two Ordinal.principal_mul_of_le_twoₓ'. -/
 theorem principal_mul_of_le_two {o : Ordinal} (ho : o ≤ 2) : Principal (· * ·) o :=
   by
   rcases lt_or_eq_of_le ho with (ho | rfl)
@@ -317,6 +425,12 @@ theorem principal_mul_of_le_two {o : Ordinal} (ho : o ≤ 2) : Principal (· * 
   · exact principal_mul_two
 #align ordinal.principal_mul_of_le_two Ordinal.principal_mul_of_le_two
 
+/- warning: ordinal.principal_add_of_principal_mul -> Ordinal.principal_add_of_principal_mul is a dubious translation:
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+Case conversion may be inaccurate. Consider using '#align ordinal.principal_add_of_principal_mul Ordinal.principal_add_of_principal_mulₓ'. -/
 theorem principal_add_of_principal_mul {o : Ordinal} (ho : Principal (· * ·) o) (ho₂ : o ≠ 2) :
     Principal (· + ·) o := by
   cases' lt_or_gt_of_ne ho₂ with ho₁ ho₂
@@ -328,11 +442,23 @@ theorem principal_add_of_principal_mul {o : Ordinal} (ho : Principal (· * ·) o
     exact add_le_add (le_max_left a b) (le_max_right a b)
 #align ordinal.principal_add_of_principal_mul Ordinal.principal_add_of_principal_mul
 
+/- warning: ordinal.principal_mul_is_limit -> Ordinal.principal_mul_isLimit is a dubious translation:
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 theorem principal_mul_isLimit {o : Ordinal.{u}} (ho₂ : 2 < o) (ho : Principal (· * ·) o) :
     o.IsLimit :=
   principal_add_isLimit ((lt_succ 1).trans ho₂) (principal_add_of_principal_mul ho (ne_of_gt ho₂))
 #align ordinal.principal_mul_is_limit Ordinal.principal_mul_isLimit
 
+/- warning: ordinal.principal_mul_iff_mul_left_eq -> Ordinal.principal_mul_iff_mul_left_eq is a dubious translation:
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+  forall {o : Ordinal.{u1}}, Iff (Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) o) (forall (a : Ordinal.{u1}), (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) (OfNat.ofNat.{succ u1} Ordinal.{u1} 0 (OfNat.mk.{succ u1} Ordinal.{u1} 0 (Zero.zero.{succ u1} Ordinal.{u1} Ordinal.hasZero.{u1}))) a) -> (LT.lt.{succ u1} Ordinal.{u1} (Preorder.toLT.{succ u1} Ordinal.{u1} (PartialOrder.toPreorder.{succ u1} Ordinal.{u1} Ordinal.partialOrder.{u1})) a o) -> (Eq.{succ (succ u1)} Ordinal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) a o) o))
+but is expected to have type
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+Case conversion may be inaccurate. Consider using '#align ordinal.principal_mul_iff_mul_left_eq Ordinal.principal_mul_iff_mul_left_eqₓ'. -/
 theorem principal_mul_iff_mul_left_eq {o : Ordinal} :
     Principal (· * ·) o ↔ ∀ a, 0 < a → a < o → a * o = o :=
   by
@@ -351,6 +477,12 @@ theorem principal_mul_iff_mul_left_eq {o : Ordinal} :
     exact (mul_is_normal ha).StrictMono hbo
 #align ordinal.principal_mul_iff_mul_left_eq Ordinal.principal_mul_iff_mul_left_eq
 
+/- warning: ordinal.principal_mul_omega -> Ordinal.principal_mul_omega is a dubious translation:
+lean 3 declaration is
+  Ordinal.Principal.{u1} (HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toHasMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1}))))) Ordinal.omega.{u1}
+but is expected to have type
+  Ordinal.Principal.{u1} (fun (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3849 : Ordinal.{u1}) (x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3851 : Ordinal.{u1}) => HMul.hMul.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHMul.{succ u1} Ordinal.{u1} (MulZeroClass.toMul.{succ u1} Ordinal.{u1} (MulZeroOneClass.toMulZeroClass.{succ u1} Ordinal.{u1} (MonoidWithZero.toMulZeroOneClass.{succ u1} Ordinal.{u1} Ordinal.monoidWithZero.{u1})))) x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3849 x._@.Mathlib.SetTheory.Ordinal.Principal._hyg.3851) Ordinal.omega.{u1}
+Case conversion may be inaccurate. Consider using '#align ordinal.principal_mul_omega Ordinal.principal_mul_omegaₓ'. -/
 theorem principal_mul_omega : Principal (· * ·) omega := fun a b ha hb =>
   match a, b, lt_omega.1 ha, lt_omega.1 hb with
   | _, _, ⟨m, rfl⟩, ⟨n, rfl⟩ => by
@@ -358,10 +490,22 @@ theorem principal_mul_omega : Principal (· * ·) omega := fun a b ha hb =>
     apply nat_lt_omega
 #align ordinal.principal_mul_omega Ordinal.principal_mul_omega
 
+/- warning: ordinal.mul_omega -> Ordinal.mul_omega is a dubious translation:
+lean 3 declaration is
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+but is expected to have type
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+Case conversion may be inaccurate. Consider using '#align ordinal.mul_omega Ordinal.mul_omegaₓ'. -/
 theorem mul_omega {a : Ordinal} (a0 : 0 < a) (ha : a < omega) : a * omega = omega :=
   principal_mul_iff_mul_left_eq.1 principal_mul_omega a a0 ha
 #align ordinal.mul_omega Ordinal.mul_omega
 
+/- warning: ordinal.mul_lt_omega_opow -> Ordinal.mul_lt_omega_opow is a dubious translation:
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+Case conversion may be inaccurate. Consider using '#align ordinal.mul_lt_omega_opow Ordinal.mul_lt_omega_opowₓ'. -/
 theorem mul_lt_omega_opow {a b c : Ordinal} (c0 : 0 < c) (ha : a < (omega^c)) (hb : b < omega) :
     a * b < (omega^c) :=
   by
@@ -378,6 +522,12 @@ theorem mul_lt_omega_opow {a b c : Ordinal} (c0 : 0 < c) (ha : a < (omega^c)) (h
     exact l.2 _ hx
 #align ordinal.mul_lt_omega_opow Ordinal.mul_lt_omega_opow
 
+/- warning: ordinal.mul_omega_opow_opow -> Ordinal.mul_omega_opow_opow is a dubious translation:
+lean 3 declaration is
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+Case conversion may be inaccurate. Consider using '#align ordinal.mul_omega_opow_opow Ordinal.mul_omega_opow_opowₓ'. -/
 theorem mul_omega_opow_opow {a b : Ordinal} (a0 : 0 < a) (h : a < (omega^omega^b)) :
     a * (omega^omega^b) = (omega^omega^b) :=
   by
@@ -392,10 +542,22 @@ theorem mul_omega_opow_opow {a b : Ordinal} (a0 : 0 < a) (h : a < (omega^omega^b
   rw [← opow_add, add_omega_opow xb]
 #align ordinal.mul_omega_opow_opow Ordinal.mul_omega_opow_opow
 
+/- warning: ordinal.principal_mul_omega_opow_opow -> Ordinal.principal_mul_omega_opow_opow is a dubious translation:
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+Case conversion may be inaccurate. Consider using '#align ordinal.principal_mul_omega_opow_opow Ordinal.principal_mul_omega_opow_opowₓ'. -/
 theorem principal_mul_omega_opow_opow (o : Ordinal) : Principal (· * ·) (omega^omega^o) :=
   principal_mul_iff_mul_left_eq.2 fun a => mul_omega_opow_opow
 #align ordinal.principal_mul_omega_opow_opow Ordinal.principal_mul_omega_opow_opow
 
+/- warning: ordinal.principal_add_of_principal_mul_opow -> Ordinal.principal_add_of_principal_mul_opow is a dubious translation:
+lean 3 declaration is
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+but is expected to have type
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+Case conversion may be inaccurate. Consider using '#align ordinal.principal_add_of_principal_mul_opow Ordinal.principal_add_of_principal_mul_opowₓ'. -/
 theorem principal_add_of_principal_mul_opow {o b : Ordinal} (hb : 1 < b)
     (ho : Principal (· * ·) (b^o)) : Principal (· + ·) o := fun x y hx hy =>
   by
@@ -403,6 +565,12 @@ theorem principal_add_of_principal_mul_opow {o b : Ordinal} (hb : 1 < b)
   rwa [← opow_add, opow_lt_opow_iff_right hb] at this
 #align ordinal.principal_add_of_principal_mul_opow Ordinal.principal_add_of_principal_mul_opow
 
+/- warning: ordinal.principal_mul_iff_le_two_or_omega_opow_opow -> Ordinal.principal_mul_iff_le_two_or_omega_opow_opow is a dubious translation:
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+Case conversion may be inaccurate. Consider using '#align ordinal.principal_mul_iff_le_two_or_omega_opow_opow Ordinal.principal_mul_iff_le_two_or_omega_opow_opowₓ'. -/
 /-- The main characterization theorem for multiplicative principal ordinals. -/
 theorem principal_mul_iff_le_two_or_omega_opow_opow {o : Ordinal} :
     Principal (· * ·) o ↔ o ≤ 2 ∨ ∃ a, o = (omega^omega^a) :=
@@ -424,10 +592,22 @@ theorem principal_mul_iff_le_two_or_omega_opow_opow {o : Ordinal} :
     · exact principal_mul_omega_opow_opow a
 #align ordinal.principal_mul_iff_le_two_or_omega_opow_opow Ordinal.principal_mul_iff_le_two_or_omega_opow_opow
 
+/- warning: ordinal.mul_omega_dvd -> Ordinal.mul_omega_dvd is a dubious translation:
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+Case conversion may be inaccurate. Consider using '#align ordinal.mul_omega_dvd Ordinal.mul_omega_dvdₓ'. -/
 theorem mul_omega_dvd {a : Ordinal} (a0 : 0 < a) (ha : a < omega) : ∀ {b}, omega ∣ b → a * b = b
   | _, ⟨b, rfl⟩ => by rw [← mul_assoc, mul_omega a0 ha]
 #align ordinal.mul_omega_dvd Ordinal.mul_omega_dvd
 
+/- warning: ordinal.mul_eq_opow_log_succ -> Ordinal.mul_eq_opow_log_succ is a dubious translation:
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+Case conversion may be inaccurate. Consider using '#align ordinal.mul_eq_opow_log_succ Ordinal.mul_eq_opow_log_succₓ'. -/
 theorem mul_eq_opow_log_succ {a b : Ordinal.{u}} (ha : a ≠ 0) (hb : Principal (· * ·) b)
     (hb₂ : 2 < b) : a * b = (b^succ (log b a)) :=
   by
@@ -449,6 +629,12 @@ theorem mul_eq_opow_log_succ {a b : Ordinal.{u}} (ha : a ≠ 0) (hb : Principal
 /-! #### Exponential principal ordinals -/
 
 
+/- warning: ordinal.principal_opow_omega -> Ordinal.principal_opow_omega is a dubious translation:
+lean 3 declaration is
+  Ordinal.Principal.{u1} (fun (_x : Ordinal.{u1}) (_y : Ordinal.{u1}) => HPow.hPow.{succ u1, succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.{u1} (instHPow.{succ u1, succ u1} Ordinal.{u1} Ordinal.{u1} Ordinal.hasPow.{u1}) _x _y) Ordinal.omega.{u1}
+but is expected to have type
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+Case conversion may be inaccurate. Consider using '#align ordinal.principal_opow_omega Ordinal.principal_opow_omegaₓ'. -/
 theorem principal_opow_omega : Principal (·^·) omega := fun a b ha hb =>
   match a, b, lt_omega.1 ha, lt_omega.1 hb with
   | _, _, ⟨m, rfl⟩, ⟨n, rfl⟩ => by
@@ -456,6 +642,12 @@ theorem principal_opow_omega : Principal (·^·) omega := fun a b ha hb =>
     apply nat_lt_omega
 #align ordinal.principal_opow_omega Ordinal.principal_opow_omega
 
+/- warning: ordinal.opow_omega -> Ordinal.opow_omega is a dubious translation:
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+Case conversion may be inaccurate. Consider using '#align ordinal.opow_omega Ordinal.opow_omegaₓ'. -/
 theorem opow_omega {a : Ordinal} (a1 : 1 < a) (h : a < omega) : (a^omega) = omega :=
   le_antisymm
     ((opow_le_of_limit (one_le_iff_ne_zero.1 <| le_of_lt a1) omega_isLimit).2 fun b hb =>

Changes in mathlib4

mathlib3
mathlib4
chore: remove unnecessary cdots (#12417)

These · are scoping when there is a single active goal.

These were found using a modification of the linter at #12339.

Diff
@@ -251,11 +251,11 @@ theorem mul_principal_add_is_principal_add (a : Ordinal.{u}) {b : Ordinal.{u}} (
     · rw [← succ_le_iff, succ_zero] at hb₁'
       intro c d hc hd
       rw [lt_mul_of_limit (principal_add_isLimit (lt_of_le_of_ne hb₁' hb₁.symm) hb)] at *
-      · rcases hc with ⟨x, hx, hx'⟩
-        rcases hd with ⟨y, hy, hy'⟩
-        use x + y, hb hx hy
-        rw [mul_add]
-        exact Left.add_lt_add hx' hy'
+      rcases hc with ⟨x, hx, hx'⟩
+      rcases hd with ⟨y, hy, hy'⟩
+      use x + y, hb hx hy
+      rw [mul_add]
+      exact Left.add_lt_add hx' hy'
 #align ordinal.mul_principal_add_is_principal_add Ordinal.mul_principal_add_is_principal_add
 
 /-! #### Multiplicative principal ordinals -/
chore: Rename nat_cast/int_cast/rat_cast to natCast/intCast/ratCast (#11486)

Now that I am defining NNRat.cast, I want a definitive answer to this naming issue. Plenty of lemmas in mathlib already use natCast/intCast/ratCast over nat_cast/int_cast/rat_cast, and this matches with the general expectation that underscore-separated name parts correspond to a single declaration.

Diff
@@ -323,7 +323,7 @@ theorem principal_mul_iff_mul_left_eq {o : Ordinal} :
 theorem principal_mul_omega : Principal (· * ·) omega := fun a b ha hb =>
   match a, b, lt_omega.1 ha, lt_omega.1 hb with
   | _, _, ⟨m, rfl⟩, ⟨n, rfl⟩ => by
-    dsimp only; rw [← nat_cast_mul]
+    dsimp only; rw [← natCast_mul]
     apply nat_lt_omega
 #align ordinal.principal_mul_omega Ordinal.principal_mul_omega
 
@@ -415,7 +415,7 @@ theorem mul_eq_opow_log_succ {a b : Ordinal.{u}} (ha : a ≠ 0) (hb : Principal
 theorem principal_opow_omega : Principal (·^·) omega := fun a b ha hb =>
   match a, b, lt_omega.1 ha, lt_omega.1 hb with
   | _, _, ⟨m, rfl⟩, ⟨n, rfl⟩ => by
-    simp_rw [← nat_cast_opow]
+    simp_rw [← natCast_opow]
     apply nat_lt_omega
 #align ordinal.principal_opow_omega Ordinal.principal_opow_omega
 
chore: tidy various files (#11490)
Diff
@@ -149,7 +149,7 @@ theorem principal_add_iff_add_left_eq_self {o : Ordinal} :
 #align ordinal.principal_add_iff_add_left_eq_self Ordinal.principal_add_iff_add_left_eq_self
 
 theorem exists_lt_add_of_not_principal_add {a} (ha : ¬Principal (· + ·) a) :
-    ∃ (b c : _) (_ : b < a) (_ : c < a), b + c = a := by
+    ∃ b c, b < a ∧ c < a ∧ b + c = a := by
   unfold Principal at ha
   push_neg at ha
   rcases ha with ⟨b, c, hb, hc, H⟩
chore: add lemmas for nat literals corresponding to lemmas for nat casts (#8006)

I loogled for every occurrence of "cast", Nat and "natCast" and where the casted nat was n, and made sure there were corresponding @[simp] lemmas for 0, 1, and OfNat.ofNat n. This is necessary in general for simp confluence. Example:

import Mathlib

variable {α : Type*} [LinearOrderedRing α] (m n : ℕ) [m.AtLeastTwo] [n.AtLeastTwo]

example : ((OfNat.ofNat m : ℕ) : α) ≤ ((OfNat.ofNat n : ℕ) : α) ↔ (OfNat.ofNat m : ℕ) ≤ (OfNat.ofNat n : ℕ) := by
  simp only [Nat.cast_le] -- this `@[simp]` lemma can apply

example : ((OfNat.ofNat m : ℕ) : α) ≤ ((OfNat.ofNat n : ℕ) : α) ↔ (OfNat.ofNat m : α) ≤ (OfNat.ofNat n : α) := by
  simp only [Nat.cast_ofNat] -- and so can this one

example : (OfNat.ofNat m : α) ≤ (OfNat.ofNat n : α) ↔ (OfNat.ofNat m : ℕ) ≤ (OfNat.ofNat n : ℕ) := by
  simp -- fails! `simp` doesn't have a lemma to bridge their results. confluence issue.

As far as I know, the only file this PR leaves with ofNat gaps is PartENat.lean. #8002 is addressing that file in parallel.

Co-authored-by: Eric Wieser <wieser.eric@gmail.com>

Diff
@@ -381,8 +381,7 @@ theorem principal_mul_iff_le_two_or_omega_opow_opow {o : Ordinal} :
     rcases principal_add_iff_zero_or_omega_opow.1
         (principal_add_of_principal_mul_opow one_lt_omega ho) with
       (rfl | ⟨b, rfl⟩)
-    · left
-      simpa using one_le_two
+    · simp
     exact Or.inr ⟨b, rfl⟩
   · rintro (ho₂ | ⟨a, rfl⟩)
     · exact principal_mul_of_le_two ho₂
chore: remove stream-of-consciousness uses of have, replace and suffices (#10640)

No changes to tactic file, it's just boring fixes throughout the library.

This follows on from #6964.

Co-authored-by: sgouezel <sebastien.gouezel@univ-rennes1.fr> Co-authored-by: Eric Wieser <wieser.eric@gmail.com>

Diff
@@ -218,8 +218,8 @@ theorem principal_add_iff_zero_or_omega_opow {o : Ordinal} :
     clear ao
     revert h'
     apply not_lt_of_le
-    suffices e : (omega^log omega o) * ↑n + o = o
-    · simpa only [e] using le_add_right ((omega^log omega o) * ↑n) o
+    suffices e : (omega^log omega o) * ↑n + o = o by
+      simpa only [e] using le_add_right ((omega^log omega o) * ↑n) o
     induction' n with n IH
     · simp [Nat.cast_zero, mul_zero, zero_add]
     simp only [Nat.cast_succ, mul_add_one, add_assoc, this, IH]
chore: remove uses of cases' (#9171)

I literally went through and regex'd some uses of cases', replacing them with rcases; this is meant to be a low effort PR as I hope that tools can do this in the future.

rcases is an easier replacement than cases, though with better tools we could in future do a second pass converting simple rcases added here (and existing ones) to cases.

Diff
@@ -128,7 +128,7 @@ theorem principal_add_isLimit {o : Ordinal} (ho₁ : 1 < o) (ho : Principal (·
   refine' ⟨fun ho₀ => _, fun a hao => _⟩
   · rw [ho₀] at ho₁
     exact not_lt_of_gt zero_lt_one ho₁
-  · cases' eq_or_ne a 0 with ha ha
+  · rcases eq_or_ne a 0 with ha | ha
     · rw [ha, succ_zero]
       exact ho₁
     · refine' lt_of_le_of_lt _ (ho hao hao)
@@ -373,7 +373,7 @@ theorem principal_add_of_principal_mul_opow {o b : Ordinal} (hb : 1 < b)
 theorem principal_mul_iff_le_two_or_omega_opow_opow {o : Ordinal} :
     Principal (· * ·) o ↔ o ≤ 2 ∨ ∃ a : Ordinal, o = (omega^omega^a) := by
   refine' ⟨fun ho => _, _⟩
-  · cases' le_or_lt o 2 with ho₂ ho₂
+  · rcases le_or_lt o 2 with ho₂ | ho₂
     · exact Or.inl ho₂
     rcases principal_add_iff_zero_or_omega_opow.1 (principal_add_of_principal_mul ho ho₂.ne') with
       (rfl | ⟨a, rfl⟩)
chore: Replace (· op ·) a by (a op ·) (#8843)

I used the regex \(\(· (.) ·\) (.)\), replacing with ($2 $1 ·).

Diff
@@ -397,9 +397,7 @@ theorem mul_eq_opow_log_succ {a b : Ordinal.{u}} (ha : a ≠ 0) (hb : Principal
     (hb₂ : 2 < b) : a * b = (b^succ (log b a)) := by
   apply le_antisymm
   · have hbl := principal_mul_isLimit hb₂ hb
-    have := IsNormal.bsup_eq.{u, u} (mul_isNormal (Ordinal.pos_iff_ne_zero.2 ha)) hbl
-    dsimp at this
-    rw [← this, bsup_le_iff]
+    rw [← IsNormal.bsup_eq.{u, u} (mul_isNormal (Ordinal.pos_iff_ne_zero.2 ha)) hbl, bsup_le_iff]
     intro c hcb
     have hb₁ : 1 < b := (lt_succ 1).trans (by simpa using hb₂)
     have hbo₀ : (b^b.log a) ≠ 0 := Ordinal.pos_iff_ne_zero.1 (opow_pos _ (zero_lt_one.trans hb₁))
chore: rename by_contra' to by_contra! (#8797)

To fit with the "please try harder" convention of ! tactics.

Co-authored-by: Scott Morrison <scott.morrison@gmail.com>

Diff
@@ -162,7 +162,7 @@ theorem exists_lt_add_of_not_principal_add {a} (ha : ¬Principal (· + ·) a) :
 theorem principal_add_iff_add_lt_ne_self {a} :
     Principal (· + ·) a ↔ ∀ ⦃b c⦄, b < a → c < a → b + c ≠ a :=
   ⟨fun ha b c hb hc => (ha hb hc).ne, fun H => by
-    by_contra' ha
+    by_contra! ha
     rcases exists_lt_add_of_not_principal_add ha with ⟨b, c, hb, hc, rfl⟩
     exact (H hb hc).irrefl⟩
 #align ordinal.principal_add_iff_add_lt_ne_self Ordinal.principal_add_iff_add_lt_ne_self
chore: bump to v4.3.0-rc2 (#8366)

PR contents

This is the supremum of

along with some minor fixes from failures on nightly-testing as Mathlib master is merged into it.

Note that some PRs for changes that are already compatible with the current toolchain and will be necessary have already been split out: #8380.

I am hopeful that in future we will be able to progressively merge adaptation PRs into a bump/v4.X.0 branch, so we never end up with a "big merge" like this. However one of these adaptation PRs (#8056) predates my new scheme for combined CI, and it wasn't possible to keep that PR viable in the meantime.

Lean PRs involved in this bump

In particular this includes adjustments for the Lean PRs

leanprover/lean4#2778

We can get rid of all the

local macro_rules | `($x ^ $y) => `(HPow.hPow $x $y) -- Porting note: See issue [lean4#2220](https://github.com/leanprover/lean4/pull/2220)

macros across Mathlib (and in any projects that want to write natural number powers of reals).

leanprover/lean4#2722

Changes the default behaviour of simp to (config := {decide := false}). This makes simp (and consequentially norm_num) less powerful, but also more consistent, and less likely to blow up in long failures. This requires a variety of changes: changing some previously by simp or norm_num to decide or rfl, or adding (config := {decide := true}).

leanprover/lean4#2783

This changed the behaviour of simp so that simp [f] will only unfold "fully applied" occurrences of f. The old behaviour can be recovered with simp (config := { unfoldPartialApp := true }). We may in future add a syntax for this, e.g. simp [!f]; please provide feedback! In the meantime, we have made the following changes:

  • switching to using explicit lemmas that have the intended level of application
  • (config := { unfoldPartialApp := true }) in some places, to recover the old behaviour
  • Using @[eqns] to manually adjust the equation lemmas for a particular definition, recovering the old behaviour just for that definition. See #8371, where we do this for Function.comp and Function.flip.

This change in Lean may require further changes down the line (e.g. adding the !f syntax, and/or upstreaming the special treatment for Function.comp and Function.flip, and/or removing this special treatment). Please keep an open and skeptical mind about these changes!

Co-authored-by: leanprover-community-mathlib4-bot <leanprover-community-mathlib4-bot@users.noreply.github.com> Co-authored-by: Scott Morrison <scott.morrison@gmail.com> Co-authored-by: Eric Wieser <wieser.eric@gmail.com> Co-authored-by: Mauricio Collares <mauricio@collares.org>

Diff
@@ -202,7 +202,7 @@ theorem principal_add_omega_opow (o : Ordinal) : Principal (· + ·) (omega^o) :
 
 /-- The main characterization theorem for additive principal ordinals. -/
 theorem principal_add_iff_zero_or_omega_opow {o : Ordinal} :
-    Principal (· + ·) o ↔ o = 0 ∨ ∃ a, o = (omega^a) := by
+    Principal (· + ·) o ↔ o = 0 ∨ ∃ a : Ordinal, o = (omega^a) := by
   rcases eq_or_ne o 0 with (rfl | ho)
   · simp only [principal_zero, Or.inl]
   · rw [principal_add_iff_add_left_eq_self]
@@ -371,7 +371,7 @@ theorem principal_add_of_principal_mul_opow {o b : Ordinal} (hb : 1 < b)
 
 /-- The main characterization theorem for multiplicative principal ordinals. -/
 theorem principal_mul_iff_le_two_or_omega_opow_opow {o : Ordinal} :
-    Principal (· * ·) o ↔ o ≤ 2 ∨ ∃ a, o = (omega^omega^a) := by
+    Principal (· * ·) o ↔ o ≤ 2 ∨ ∃ a : Ordinal, o = (omega^omega^a) := by
   refine' ⟨fun ho => _, _⟩
   · cases' le_or_lt o 2 with ho₂ ho₂
     · exact Or.inl ho₂
chore: missing spaces after rcases, convert and congrm (#7725)

Replace rcases( with rcases (. Same thing for convert( and congrm(. No other change.

Diff
@@ -184,10 +184,10 @@ theorem add_omega_opow {a b : Ordinal} (h : a < (omega^b)) : a + (omega^b) = (om
   · rw [opow_zero, ← succ_zero, lt_succ_iff, Ordinal.le_zero] at h
     rw [h, zero_add]
   · rw [opow_succ] at h
-    rcases(lt_mul_of_limit omega_isLimit).1 h with ⟨x, xo, ax⟩
+    rcases (lt_mul_of_limit omega_isLimit).1 h with ⟨x, xo, ax⟩
     refine' le_trans (add_le_add_right (le_of_lt ax) _) _
     rw [opow_succ, ← mul_add, add_omega xo]
-  · rcases(lt_opow_of_limit omega_ne_zero l).1 h with ⟨x, xb, ax⟩
+  · rcases (lt_opow_of_limit omega_ne_zero l).1 h with ⟨x, xb, ax⟩
     exact
       (((add_isNormal a).trans (opow_isNormal one_lt_omega)).limit_le l).2 fun y yb =>
         (add_le_add_left (opow_le_opow_right omega_pos (le_max_right _ _)) _).trans
@@ -336,11 +336,11 @@ theorem mul_lt_omega_opow {a b c : Ordinal} (c0 : 0 < c) (ha : a < (omega^c)) (h
   rcases zero_or_succ_or_limit c with (rfl | ⟨c, rfl⟩ | l)
   · exact (lt_irrefl _).elim c0
   · rw [opow_succ] at ha
-    rcases((mul_isNormal <| opow_pos _ omega_pos).limit_lt omega_isLimit).1 ha with ⟨n, hn, an⟩
+    rcases ((mul_isNormal <| opow_pos _ omega_pos).limit_lt omega_isLimit).1 ha with ⟨n, hn, an⟩
     apply (mul_le_mul_right' (le_of_lt an) _).trans_lt
     rw [opow_succ, mul_assoc, mul_lt_mul_iff_left (opow_pos _ omega_pos)]
     exact principal_mul_omega hn hb
-  · rcases((opow_isNormal one_lt_omega).limit_lt l).1 ha with ⟨x, hx, ax⟩
+  · rcases ((opow_isNormal one_lt_omega).limit_lt l).1 ha with ⟨x, hx, ax⟩
     refine' (mul_le_mul' (le_of_lt ax) (le_of_lt hb)).trans_lt _
     rw [← opow_succ, opow_lt_opow_iff_right one_lt_omega]
     exact l.2 _ hx
@@ -354,7 +354,7 @@ theorem mul_omega_opow_opow {a b : Ordinal} (a0 : 0 < a) (h : a < (omega^omega^b
   refine'
     le_antisymm _
       (by simpa only [one_mul] using mul_le_mul_right' (one_le_iff_pos.2 a0) (omega^omega^b))
-  rcases(lt_opow_of_limit omega_ne_zero (opow_isLimit_left omega_isLimit b0)).1 h with ⟨x, xb, ax⟩
+  rcases (lt_opow_of_limit omega_ne_zero (opow_isLimit_left omega_isLimit b0)).1 h with ⟨x, xb, ax⟩
   apply (mul_le_mul_right' (le_of_lt ax) _).trans
   rw [← opow_add, add_omega_opow xb]
 #align ordinal.mul_omega_opow_opow Ordinal.mul_omega_opow_opow
chore: script to replace headers with #align_import statements (#5979)

Open in Gitpod

Co-authored-by: Eric Wieser <wieser.eric@gmail.com> Co-authored-by: Scott Morrison <scott.morrison@gmail.com>

Diff
@@ -2,14 +2,11 @@
 Copyright (c) 2022 Violeta Hernández Palacios. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Violeta Hernández Palacios
-
-! This file was ported from Lean 3 source module set_theory.ordinal.principal
-! leanprover-community/mathlib commit 31b269b60935483943542d547a6dd83a66b37dc7
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathlib.SetTheory.Ordinal.FixedPoint
 
+#align_import set_theory.ordinal.principal from "leanprover-community/mathlib"@"31b269b60935483943542d547a6dd83a66b37dc7"
+
 /-!
 ### Principal ordinals
 
chore: partial forward port of 14324 (#5954)

This doesn't yet forward port the changes to Mathlib/SetTheory/Ordinal/NaturalOps.lean.

Co-authored-by: Scott Morrison <scott.morrison@gmail.com>

Diff
@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Violeta Hernández Palacios
 
 ! This file was ported from Lean 3 source module set_theory.ordinal.principal
-! leanprover-community/mathlib commit 9b2660e1b25419042c8da10bf411aa3c67f14383
+! leanprover-community/mathlib commit 31b269b60935483943542d547a6dd83a66b37dc7
 ! Please do not edit these lines, except to modify the commit id
 ! if you have ported upstream changes.
 -/
@@ -91,35 +91,21 @@ theorem nfp_le_of_principal {op : Ordinal → Ordinal → Ordinal} {a o : Ordina
 
 /-! ### Principal ordinals are unbounded -/
 
-
-/-- The least strict upper bound of `op` applied to all pairs of ordinals less than `o`. This is
-essentially a two-argument version of `Ordinal.blsub`. -/
-def blsub₂ (op : Ordinal → Ordinal → Ordinal) (o : Ordinal) : Ordinal :=
-  lsub fun x : o.out.α × o.out.α => op (typein LT.lt x.1) (typein LT.lt x.2)
-#align ordinal.blsub₂ Ordinal.blsub₂
-
-theorem lt_blsub₂ (op : Ordinal.{u} → Ordinal.{u} → Ordinal.{max u v})
-  {o a b : Ordinal.{u}} (ha : a < o)
-    (hb : b < o) : op a b < blsub₂.{u, v} op o := by
-  convert lt_lsub.{v, u}
-      (fun x : (Quotient.out.{u+2} o).α × (Quotient.out.{u+2} o).α =>
-        op (typein.{u} LT.lt x.fst) (typein.{u} LT.lt x.snd))
-      (Prod.mk.{u, u} (enum.{u} LT.lt a (by rwa [type_lt])) (enum.{u} LT.lt b (by rwa [type_lt])))
-  <;> simp only [typein_enum]
-#align ordinal.lt_blsub₂ Ordinal.lt_blsub₂
-
 theorem principal_nfp_blsub₂ (op : Ordinal → Ordinal → Ordinal) (o : Ordinal) :
-    Principal op (nfp (blsub₂.{u, u} op) o) := fun a b ha hb => by
+    Principal op (nfp (fun o' => blsub₂.{u, u, u} o' o' (@fun a _ b _ => op a b)) o) :=
+  fun a b ha hb => by
   rw [lt_nfp] at *
   cases' ha with m hm
   cases' hb with n hn
-  cases' le_total ((blsub₂.{u, u} op)^[m] o) ((blsub₂.{u, u} op)^[n] o) with h h
+  cases' le_total
+    ((fun o' => blsub₂.{u, u, u} o' o' (@fun a _ b _ => op a b))^[m] o)
+    ((fun o' => blsub₂.{u, u, u} o' o' (@fun a _ b _ => op a b))^[n] o) with h h
   · use n + 1
     rw [Function.iterate_succ']
-    exact lt_blsub₂ op (hm.trans_le h) hn
+    exact lt_blsub₂ (@fun a _ b _ => op a b) (hm.trans_le h) hn
   · use m + 1
     rw [Function.iterate_succ']
-    exact lt_blsub₂ op hm (hn.trans_le h)
+    exact lt_blsub₂ (@fun a _ b _ => op a b) hm (hn.trans_le h)
 #align ordinal.principal_nfp_blsub₂ Ordinal.principal_nfp_blsub₂
 
 theorem unbounded_principal (op : Ordinal → Ordinal → Ordinal) :
fix precedence of Nat.iterate (#5589)
Diff
@@ -70,7 +70,7 @@ theorem principal_one_iff {op : Ordinal → Ordinal → Ordinal} : Principal op
 #align ordinal.principal_one_iff Ordinal.principal_one_iff
 
 theorem Principal.iterate_lt {op : Ordinal → Ordinal → Ordinal} {a o : Ordinal} (hao : a < o)
-    (ho : Principal op o) (n : ℕ) : (op a^[n]) a < o := by
+    (ho : Principal op o) (n : ℕ) : (op a)^[n] a < o := by
   induction' n with n hn
   · rwa [Function.iterate_zero]
   · rw [Function.iterate_succ']
@@ -113,7 +113,7 @@ theorem principal_nfp_blsub₂ (op : Ordinal → Ordinal → Ordinal) (o : Ordin
   rw [lt_nfp] at *
   cases' ha with m hm
   cases' hb with n hn
-  cases' le_total ((blsub₂.{u, u} op^[m]) o) ((blsub₂.{u, u} op^[n]) o) with h h
+  cases' le_total ((blsub₂.{u, u} op)^[m] o) ((blsub₂.{u, u} op)^[n] o) with h h
   · use n + 1
     rw [Function.iterate_succ']
     exact lt_blsub₂ op (hm.trans_le h) hn
chore: clean up spacing around at and goals (#5387)

Changes are of the form

  • some_tactic at h⊢ -> some_tactic at h ⊢
  • some_tactic at h -> some_tactic at h
Diff
@@ -168,7 +168,7 @@ theorem principal_add_iff_add_left_eq_self {o : Ordinal} :
 theorem exists_lt_add_of_not_principal_add {a} (ha : ¬Principal (· + ·) a) :
     ∃ (b c : _) (_ : b < a) (_ : c < a), b + c = a := by
   unfold Principal at ha
-  push_neg  at ha
+  push_neg at ha
   rcases ha with ⟨b, c, hb, hc, H⟩
   refine'
     ⟨b, _, hb, lt_of_le_of_ne (sub_le_self a b) fun hab => _, Ordinal.add_sub_cancel_of_le hb.le⟩
@@ -366,7 +366,7 @@ theorem mul_lt_omega_opow {a b c : Ordinal} (c0 : 0 < c) (ha : a < (omega^c)) (h
 theorem mul_omega_opow_opow {a b : Ordinal} (a0 : 0 < a) (h : a < (omega^omega^b)) :
     a * (omega^omega^b) = (omega^omega^b) := by
   by_cases b0 : b = 0;
-  · rw [b0, opow_zero, opow_one] at h⊢
+  · rw [b0, opow_zero, opow_one] at h ⊢
     exact mul_omega a0 h
   refine'
     le_antisymm _
chore: convert lambda in docs to fun (#5045)

Found with git grep -n "λ [a-zA-Z_ ]*,"

Diff
@@ -26,7 +26,7 @@ We define principal or indecomposable ordinals, and we prove the standard proper
 
 ### Todo
 * Prove that exponential principal ordinals are 0, 1, 2, ω, or epsilon numbers, i.e. fixed points
-  of `λ x, ω ^ x`.
+  of `fun x ↦ ω ^ x`.
 -/
 
 universe u v w
chore: formatting issues (#4947)

Co-authored-by: Scott Morrison <scott.morrison@anu.edu.au> Co-authored-by: Parcly Taxel <reddeloostw@gmail.com>

Diff
@@ -166,7 +166,7 @@ theorem principal_add_iff_add_left_eq_self {o : Ordinal} :
 #align ordinal.principal_add_iff_add_left_eq_self Ordinal.principal_add_iff_add_left_eq_self
 
 theorem exists_lt_add_of_not_principal_add {a} (ha : ¬Principal (· + ·) a) :
-    ∃ (b c : _) (_ : b < a)(_ : c < a), b + c = a := by
+    ∃ (b c : _) (_ : b < a) (_ : c < a), b + c = a := by
   unfold Principal at ha
   push_neg  at ha
   rcases ha with ⟨b, c, hb, hc, H⟩
chore: bye-bye, solo bys! (#3825)

This PR puts, with one exception, every single remaining by that lies all by itself on its own line to the previous line, thus matching the current behaviour of start-port.sh. The exception is when the by begins the second or later argument to a tuple or anonymous constructor; see https://github.com/leanprover-community/mathlib4/pull/3825#discussion_r1186702599.

Essentially this is s/\n *by$/ by/g, but with manual editing to satisfy the linter's max-100-char-line requirement. The Python style linter is also modified to catch these "isolated bys".

Diff
@@ -140,8 +140,8 @@ theorem principal_add_of_le_one {o : Ordinal} (ho : o ≤ 1) : Principal (· + 
   · exact principal_add_one
 #align ordinal.principal_add_of_le_one Ordinal.principal_add_of_le_one
 
-theorem principal_add_isLimit {o : Ordinal} (ho₁ : 1 < o) (ho : Principal (· + ·) o) : o.IsLimit :=
-  by
+theorem principal_add_isLimit {o : Ordinal} (ho₁ : 1 < o) (ho : Principal (· + ·) o) :
+    o.IsLimit := by
   refine' ⟨fun ho₀ => _, fun a hao => _⟩
   · rw [ho₀] at ho₁
     exact not_lt_of_gt zero_lt_one ho₁
@@ -178,8 +178,7 @@ theorem exists_lt_add_of_not_principal_add {a} (ha : ¬Principal (· + ·) a) :
 
 theorem principal_add_iff_add_lt_ne_self {a} :
     Principal (· + ·) a ↔ ∀ ⦃b c⦄, b < a → c < a → b + c ≠ a :=
-  ⟨fun ha b c hb hc => (ha hb hc).ne, fun H =>
-    by
+  ⟨fun ha b c hb hc => (ha hb hc).ne, fun H => by
     by_contra' ha
     rcases exists_lt_add_of_not_principal_add ha with ⟨b, c, hb, hc, rfl⟩
     exact (H hb hc).irrefl⟩
feat: port SetTheory.Ordinal.Principal (#2442)

Dependencies 7 + 308

309 files ported (97.8%)
128922 lines ported (97.7%)
Show graph

The unported dependencies are