algebra.char_zero.defs | Mathlib porting status

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

d6aae1bc

(last sync)

Changes in mathlib3port

mathlib3

mathlib3port

448144f7

bump to nightly-2024-03-17-08

mathlib commit https://github.com/leanprover-community/mathlib/commit/65a1391a0106c9204fe45bc73a039f056558cb83

22f01ce4

Diff

@@ -52,7 +52,7 @@ theorem charZero_of_inj_zero {R : Type _} [AddGroupWithOne R] (H : ∀ n : ℕ,
   ⟨fun m n h => by
     induction' m with m ih generalizing n; · rw [H n]; rw [← h, Nat.cast_zero]
     cases' n with n; · apply H; rw [h, Nat.cast_zero]
-    simp_rw [Nat.cast_succ, add_right_cancel_iff] at h ; rwa [ih]⟩
+    simp_rw [Nat.cast_succ, add_right_cancel_iff] at h; rwa [ih]⟩
 #align char_zero_of_inj_zero charZero_of_inj_zero
 -/

448144f7

bump to nightly-2023-09-24-06

mathlib commit https://github.com/leanprover-community/mathlib/commit/ce64cd319bb6b3e82f31c2d38e79080d377be451

5655435f

Diff

@@ -3,7 +3,7 @@ Copyright (c) 2014 Mario Carneiro. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Mario Carneiro
 -/
-import Mathbin.Data.Int.Cast.Defs
+import Data.Int.Cast.Defs
 
 #align_import algebra.char_zero.defs from "leanprover-community/mathlib"@"448144f7ae193a8990cb7473c9e9a01990f64ac7"

448144f7

bump to nightly-2023-07-20-09

mathlib commit https://github.com/leanprover-community/mathlib/commit/8ea5598db6caeddde6cb734aa179cc2408dbd345

9c56d0dd

Diff

@@ -2,14 +2,11 @@
 Copyright (c) 2014 Mario Carneiro. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Mario Carneiro
-
-! This file was ported from Lean 3 source module algebra.char_zero.defs
-! leanprover-community/mathlib commit 448144f7ae193a8990cb7473c9e9a01990f64ac7
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathbin.Data.Int.Cast.Defs
 
+#align_import algebra.char_zero.defs from "leanprover-community/mathlib"@"448144f7ae193a8990cb7473c9e9a01990f64ac7"
+
 /-!
 # Characteristic zero

448144f7

bump to nightly-2023-06-13-21

mathlib commit https://github.com/leanprover-community/mathlib/commit/9fb8964792b4237dac6200193a0d533f1b3f7423

829520ac

Diff

@@ -49,6 +49,7 @@ class CharZero (R : Type _) [AddMonoidWithOne R] : Prop where
 #align char_zero CharZero
 -/
 
+#print charZero_of_inj_zero /-
 theorem charZero_of_inj_zero {R : Type _} [AddGroupWithOne R] (H : ∀ n : ℕ, (n : R) = 0 → n = 0) :
     CharZero R :=
   ⟨fun m n h => by
@@ -56,6 +57,7 @@ theorem charZero_of_inj_zero {R : Type _} [AddGroupWithOne R] (H : ∀ n : ℕ,
     cases' n with n; · apply H; rw [h, Nat.cast_zero]
     simp_rw [Nat.cast_succ, add_right_cancel_iff] at h ; rwa [ih]⟩
 #align char_zero_of_inj_zero charZero_of_inj_zero
+-/
 
 namespace Nat
 
@@ -74,17 +76,23 @@ theorem cast_inj {m n : ℕ} : (m : R) = n ↔ m = n :=
 #align nat.cast_inj Nat.cast_inj
 -/
 
+#print Nat.cast_eq_zero /-
 @[simp, norm_cast]
 theorem cast_eq_zero {n : ℕ} : (n : R) = 0 ↔ n = 0 := by rw [← cast_zero, cast_inj]
 #align nat.cast_eq_zero Nat.cast_eq_zero
+-/
 
+#print Nat.cast_ne_zero /-
 @[norm_cast]
 theorem cast_ne_zero {n : ℕ} : (n : R) ≠ 0 ↔ n ≠ 0 :=
   not_congr cast_eq_zero
 #align nat.cast_ne_zero Nat.cast_ne_zero
+-/
 
+#print Nat.cast_add_one_ne_zero /-
 theorem cast_add_one_ne_zero (n : ℕ) : (n + 1 : R) ≠ 0 := by exact_mod_cast n.succ_ne_zero
 #align nat.cast_add_one_ne_zero Nat.cast_add_one_ne_zero
+-/
 
 #print Nat.cast_eq_one /-
 @[simp, norm_cast]
@@ -103,9 +111,11 @@ end Nat
 
 namespace NeZero
 
+#print NeZero.charZero /-
 instance charZero {M} {n : ℕ} [NeZero n] [AddMonoidWithOne M] [CharZero M] : NeZero (n : M) :=
   ⟨Nat.cast_ne_zero.mpr out⟩
 #align ne_zero.char_zero NeZero.charZero
+-/
 
 end NeZero

448144f7

bump to nightly-2023-06-01-16

mathlib commit https://github.com/leanprover-community/mathlib/commit/cca40788df1b8755d5baf17ab2f27dacc2e17acb

b9c87c70

Diff

@@ -54,7 +54,7 @@ theorem charZero_of_inj_zero {R : Type _} [AddGroupWithOne R] (H : ∀ n : ℕ,
   ⟨fun m n h => by
     induction' m with m ih generalizing n; · rw [H n]; rw [← h, Nat.cast_zero]
     cases' n with n; · apply H; rw [h, Nat.cast_zero]
-    simp_rw [Nat.cast_succ, add_right_cancel_iff] at h; rwa [ih]⟩
+    simp_rw [Nat.cast_succ, add_right_cancel_iff] at h ; rwa [ih]⟩
 #align char_zero_of_inj_zero charZero_of_inj_zero
 
 namespace Nat

448144f7

bump to nightly-2023-05-28-06

mathlib commit https://github.com/leanprover-community/mathlib/commit/917c3c072e487b3cccdbfeff17e75b40e45f66cb

ba5d8b97

Diff

@@ -49,12 +49,6 @@ class CharZero (R : Type _) [AddMonoidWithOne R] : Prop where
 #align char_zero CharZero
 -/
 
-/- warning: char_zero_of_inj_zero -> charZero_of_inj_zero is a dubious translation:
-lean 3 declaration is
-  forall {R : Type.{u1}} [_inst_1 : AddGroupWithOne.{u1} R], (forall (n : Nat), (Eq.{succ u1} R ((fun (a : Type) (b : Type.{u1}) [self : HasLiftT.{1, succ u1} a b] => self.0) Nat R (HasLiftT.mk.{1, succ u1} Nat R (CoeTCₓ.coe.{1, succ u1} Nat R (Nat.castCoe.{u1} R (AddMonoidWithOne.toNatCast.{u1} R (AddGroupWithOne.toAddMonoidWithOne.{u1} R _inst_1))))) n) (OfNat.ofNat.{u1} R 0 (OfNat.mk.{u1} R 0 (Zero.zero.{u1} R (AddZeroClass.toHasZero.{u1} R (AddMonoid.toAddZeroClass.{u1} R (AddMonoidWithOne.toAddMonoid.{u1} R (AddGroupWithOne.toAddMonoidWithOne.{u1} R _inst_1)))))))) -> (Eq.{1} Nat n (OfNat.ofNat.{0} Nat 0 (OfNat.mk.{0} Nat 0 (Zero.zero.{0} Nat Nat.hasZero))))) -> (CharZero.{u1} R (AddGroupWithOne.toAddMonoidWithOne.{u1} R _inst_1))
-but is expected to have type
-  forall {R : Type.{u1}} [_inst_1 : AddGroupWithOne.{u1} R], (forall (n : Nat), (Eq.{succ u1} R (Nat.cast.{u1} R (AddMonoidWithOne.toNatCast.{u1} R (AddGroupWithOne.toAddMonoidWithOne.{u1} R _inst_1)) n) (OfNat.ofNat.{u1} R 0 (Zero.toOfNat0.{u1} R (AddRightCancelMonoid.toZero.{u1} R (AddCancelMonoid.toAddRightCancelMonoid.{u1} R (AddGroup.toAddCancelMonoid.{u1} R (AddGroupWithOne.toAddGroup.{u1} R _inst_1))))))) -> (Eq.{1} Nat n (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0)))) -> (CharZero.{u1} R (AddGroupWithOne.toAddMonoidWithOne.{u1} R _inst_1))
-Case conversion may be inaccurate. Consider using '#align char_zero_of_inj_zero charZero_of_inj_zeroₓ'. -/
 theorem charZero_of_inj_zero {R : Type _} [AddGroupWithOne R] (H : ∀ n : ℕ, (n : R) = 0 → n = 0) :
     CharZero R :=
   ⟨fun m n h => by
@@ -80,33 +74,15 @@ theorem cast_inj {m n : ℕ} : (m : R) = n ↔ m = n :=
 #align nat.cast_inj Nat.cast_inj
 -/
 
-/- warning: nat.cast_eq_zero -> Nat.cast_eq_zero is a dubious translation:
-lean 3 declaration is
-  forall {R : Type.{u1}} [_inst_1 : AddMonoidWithOne.{u1} R] [_inst_2 : CharZero.{u1} R _inst_1] {n : Nat}, Iff (Eq.{succ u1} R ((fun (a : Type) (b : Type.{u1}) [self : HasLiftT.{1, succ u1} a b] => self.0) Nat R (HasLiftT.mk.{1, succ u1} Nat R (CoeTCₓ.coe.{1, succ u1} Nat R (Nat.castCoe.{u1} R (AddMonoidWithOne.toNatCast.{u1} R _inst_1)))) n) (OfNat.ofNat.{u1} R 0 (OfNat.mk.{u1} R 0 (Zero.zero.{u1} R (AddZeroClass.toHasZero.{u1} R (AddMonoid.toAddZeroClass.{u1} R (AddMonoidWithOne.toAddMonoid.{u1} R _inst_1))))))) (Eq.{1} Nat n (OfNat.ofNat.{0} Nat 0 (OfNat.mk.{0} Nat 0 (Zero.zero.{0} Nat Nat.hasZero))))
-but is expected to have type
-  forall {R : Type.{u1}} [_inst_1 : AddMonoidWithOne.{u1} R] [_inst_2 : CharZero.{u1} R _inst_1] {n : Nat}, Iff (Eq.{succ u1} R (Nat.cast.{u1} R (AddMonoidWithOne.toNatCast.{u1} R _inst_1) n) (OfNat.ofNat.{u1} R 0 (Zero.toOfNat0.{u1} R (AddMonoid.toZero.{u1} R (AddMonoidWithOne.toAddMonoid.{u1} R _inst_1))))) (Eq.{1} Nat n (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0)))
-Case conversion may be inaccurate. Consider using '#align nat.cast_eq_zero Nat.cast_eq_zeroₓ'. -/
 @[simp, norm_cast]
 theorem cast_eq_zero {n : ℕ} : (n : R) = 0 ↔ n = 0 := by rw [← cast_zero, cast_inj]
 #align nat.cast_eq_zero Nat.cast_eq_zero
 
-/- warning: nat.cast_ne_zero -> Nat.cast_ne_zero is a dubious translation:
-lean 3 declaration is
-  forall {R : Type.{u1}} [_inst_1 : AddMonoidWithOne.{u1} R] [_inst_2 : CharZero.{u1} R _inst_1] {n : Nat}, Iff (Ne.{succ u1} R ((fun (a : Type) (b : Type.{u1}) [self : HasLiftT.{1, succ u1} a b] => self.0) Nat R (HasLiftT.mk.{1, succ u1} Nat R (CoeTCₓ.coe.{1, succ u1} Nat R (Nat.castCoe.{u1} R (AddMonoidWithOne.toNatCast.{u1} R _inst_1)))) n) (OfNat.ofNat.{u1} R 0 (OfNat.mk.{u1} R 0 (Zero.zero.{u1} R (AddZeroClass.toHasZero.{u1} R (AddMonoid.toAddZeroClass.{u1} R (AddMonoidWithOne.toAddMonoid.{u1} R _inst_1))))))) (Ne.{1} Nat n (OfNat.ofNat.{0} Nat 0 (OfNat.mk.{0} Nat 0 (Zero.zero.{0} Nat Nat.hasZero))))
-but is expected to have type
-  forall {R : Type.{u1}} [_inst_1 : AddMonoidWithOne.{u1} R] [_inst_2 : CharZero.{u1} R _inst_1] {n : Nat}, Iff (Ne.{succ u1} R (Nat.cast.{u1} R (AddMonoidWithOne.toNatCast.{u1} R _inst_1) n) (OfNat.ofNat.{u1} R 0 (Zero.toOfNat0.{u1} R (AddMonoid.toZero.{u1} R (AddMonoidWithOne.toAddMonoid.{u1} R _inst_1))))) (Ne.{1} Nat n (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0)))
-Case conversion may be inaccurate. Consider using '#align nat.cast_ne_zero Nat.cast_ne_zeroₓ'. -/
 @[norm_cast]
 theorem cast_ne_zero {n : ℕ} : (n : R) ≠ 0 ↔ n ≠ 0 :=
   not_congr cast_eq_zero
 #align nat.cast_ne_zero Nat.cast_ne_zero
 
-/- warning: nat.cast_add_one_ne_zero -> Nat.cast_add_one_ne_zero is a dubious translation:
-lean 3 declaration is
-  forall {R : Type.{u1}} [_inst_1 : AddMonoidWithOne.{u1} R] [_inst_2 : CharZero.{u1} R _inst_1] (n : Nat), Ne.{succ u1} R (HAdd.hAdd.{u1, u1, u1} R R R (instHAdd.{u1} R (AddZeroClass.toHasAdd.{u1} R (AddMonoid.toAddZeroClass.{u1} R (AddMonoidWithOne.toAddMonoid.{u1} R _inst_1)))) ((fun (a : Type) (b : Type.{u1}) [self : HasLiftT.{1, succ u1} a b] => self.0) Nat R (HasLiftT.mk.{1, succ u1} Nat R (CoeTCₓ.coe.{1, succ u1} Nat R (Nat.castCoe.{u1} R (AddMonoidWithOne.toNatCast.{u1} R _inst_1)))) n) (OfNat.ofNat.{u1} R 1 (OfNat.mk.{u1} R 1 (One.one.{u1} R (AddMonoidWithOne.toOne.{u1} R _inst_1))))) (OfNat.ofNat.{u1} R 0 (OfNat.mk.{u1} R 0 (Zero.zero.{u1} R (AddZeroClass.toHasZero.{u1} R (AddMonoid.toAddZeroClass.{u1} R (AddMonoidWithOne.toAddMonoid.{u1} R _inst_1))))))
-but is expected to have type
-  forall {R : Type.{u1}} [_inst_1 : AddMonoidWithOne.{u1} R] [_inst_2 : CharZero.{u1} R _inst_1] (n : Nat), Ne.{succ u1} R (HAdd.hAdd.{u1, u1, u1} R R R (instHAdd.{u1} R (AddZeroClass.toAdd.{u1} R (AddMonoid.toAddZeroClass.{u1} R (AddMonoidWithOne.toAddMonoid.{u1} R _inst_1)))) (Nat.cast.{u1} R (AddMonoidWithOne.toNatCast.{u1} R _inst_1) n) (OfNat.ofNat.{u1} R 1 (One.toOfNat1.{u1} R (AddMonoidWithOne.toOne.{u1} R _inst_1)))) (OfNat.ofNat.{u1} R 0 (Zero.toOfNat0.{u1} R (AddMonoid.toZero.{u1} R (AddMonoidWithOne.toAddMonoid.{u1} R _inst_1))))
-Case conversion may be inaccurate. Consider using '#align nat.cast_add_one_ne_zero Nat.cast_add_one_ne_zeroₓ'. -/
 theorem cast_add_one_ne_zero (n : ℕ) : (n + 1 : R) ≠ 0 := by exact_mod_cast n.succ_ne_zero
 #align nat.cast_add_one_ne_zero Nat.cast_add_one_ne_zero
 
@@ -127,12 +103,6 @@ end Nat
 
 namespace NeZero
 
-/- warning: ne_zero.char_zero -> NeZero.charZero is a dubious translation:
-lean 3 declaration is
-  forall {M : Type.{u1}} {n : Nat} [_inst_1 : NeZero.{0} Nat Nat.hasZero n] [_inst_2 : AddMonoidWithOne.{u1} M] [_inst_3 : CharZero.{u1} M _inst_2], NeZero.{u1} M (AddZeroClass.toHasZero.{u1} M (AddMonoid.toAddZeroClass.{u1} M (AddMonoidWithOne.toAddMonoid.{u1} M _inst_2))) ((fun (a : Type) (b : Type.{u1}) [self : HasLiftT.{1, succ u1} a b] => self.0) Nat M (HasLiftT.mk.{1, succ u1} Nat M (CoeTCₓ.coe.{1, succ u1} Nat M (Nat.castCoe.{u1} M (AddMonoidWithOne.toNatCast.{u1} M _inst_2)))) n)
-but is expected to have type
-  forall {M : Type.{u1}} {n : Nat} [_inst_1 : NeZero.{0} Nat (Zero.ofOfNat0.{0} Nat (instOfNatNat 0)) n] [_inst_2 : AddMonoidWithOne.{u1} M] [_inst_3 : CharZero.{u1} M _inst_2], NeZero.{u1} M (AddMonoid.toZero.{u1} M (AddMonoidWithOne.toAddMonoid.{u1} M _inst_2)) (Nat.cast.{u1} M (AddMonoidWithOne.toNatCast.{u1} M _inst_2) n)
-Case conversion may be inaccurate. Consider using '#align ne_zero.char_zero NeZero.charZeroₓ'. -/
 instance charZero {M} {n : ℕ} [NeZero n] [AddMonoidWithOne M] [CharZero M] : NeZero (n : M) :=
   ⟨Nat.cast_ne_zero.mpr out⟩
 #align ne_zero.char_zero NeZero.charZero

448144f7

bump to nightly-2023-05-28-04

mathlib commit https://github.com/leanprover-community/mathlib/commit/917c3c072e487b3cccdbfeff17e75b40e45f66cb

6797a637

Diff

@@ -58,12 +58,8 @@ Case conversion may be inaccurate. Consider using '#align char_zero_of_inj_zero
 theorem charZero_of_inj_zero {R : Type _} [AddGroupWithOne R] (H : ∀ n : ℕ, (n : R) = 0 → n = 0) :
     CharZero R :=
   ⟨fun m n h => by
-    induction' m with m ih generalizing n;
-    · rw [H n]
-      rw [← h, Nat.cast_zero]
-    cases' n with n;
-    · apply H
-      rw [h, Nat.cast_zero]
+    induction' m with m ih generalizing n; · rw [H n]; rw [← h, Nat.cast_zero]
+    cases' n with n; · apply H; rw [h, Nat.cast_zero]
     simp_rw [Nat.cast_succ, add_right_cancel_iff] at h; rwa [ih]⟩
 #align char_zero_of_inj_zero charZero_of_inj_zero

448144f7

bump to nightly-2023-02-21-16

mathlib commit https://github.com/leanprover-community/mathlib/commit/bd9851ca476957ea4549eb19b40e7b5ade9428cc

1107b979

Changes in mathlib4

mathlib3

mathlib4

d6aae1bc

chore: remove more autoImplicit (#11336)

... or reduce its scope (the full removal is not as obvious).

59f72a90

Diff

@@ -29,8 +29,6 @@ from the natural numbers into it is injective.
 * Unify with `CharP` (possibly using an out-parameter)
 -/
 
-set_option autoImplicit true
-
 /-- Typeclass for monoids with characteristic zero.
   (This is usually stated on fields but it makes sense for any additive monoid with 1.)
 
@@ -47,6 +45,8 @@ class CharZero (R) [AddMonoidWithOne R] : Prop where
   cast_injective : Function.Injective (Nat.cast : ℕ → R)
 #align char_zero CharZero
 
+variable {R : Type*}
+
 theorem charZero_of_inj_zero [AddGroupWithOne R] (H : ∀ n : ℕ, (n : R) = 0 → n = 0) :
     CharZero R :=
   ⟨@fun m n h => by

d6aae1bc

style: homogenise porting notes (#11145)

Homogenises porting notes via capitalisation and addition of whitespace.

It makes the following changes:

converts "--porting note" into "-- Porting note";
converts "porting note" into "Porting note".

8be0b69c

Diff

@@ -85,7 +85,7 @@ theorem cast_ne_zero {n : ℕ} : (n : R) ≠ 0 ↔ n ≠ 0 :=
 #align nat.cast_ne_zero Nat.cast_ne_zero
 
 theorem cast_add_one_ne_zero (n : ℕ) : (n + 1 : R) ≠ 0 := by
-  -- porting note: old proof was `exact_mod_cast n.succ_ne_zero`
+  -- Porting note: old proof was `exact_mod_cast n.succ_ne_zero`
   norm_cast
   exact n.succ_ne_zero
 #align nat.cast_add_one_ne_zero Nat.cast_add_one_ne_zero

d6aae1bc

chore: add instance from Nat.AtLeastTwo n to NeZero n (#10964)

This PR cleans up some lemmas where we're taking named instance parameters [h : Nat.AtLeastTwo n] and manually proving inequalities like 0 < n from h by adding an instance of NeZero n from Nat.AtLeastTwo n as well as a couple of other helper lemmas.

This removes Nat.AtLeastTwo.ne_zero, as NeZero.ne_zero replaces it.

da1fa193

Diff

@@ -3,7 +3,6 @@ Copyright (c) 2014 Mario Carneiro. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Mario Carneiro
 -/
-import Mathlib.Init.Data.Nat.Lemmas
 import Mathlib.Data.Int.Cast.Defs
 import Mathlib.Tactic.Cases
 import Mathlib.Algebra.NeZero
@@ -100,21 +99,23 @@ theorem cast_ne_one {n : ℕ} : (n : R) ≠ 1 ↔ n ≠ 1 :=
   cast_eq_one.not
 #align nat.cast_ne_one Nat.cast_ne_one
 
+instance (priority := 100) AtLeastTwo.toNeZero (n : ℕ) [n.AtLeastTwo] : NeZero n :=
+  ⟨Nat.ne_of_gt (Nat.le_of_lt one_lt)⟩
+
 end Nat
 
 namespace OfNat
 
 variable [AddMonoidWithOne R] [CharZero R]
 
-@[simp] lemma ofNat_ne_zero (n : ℕ) [h : n.AtLeastTwo] : (no_index (ofNat n) : R) ≠ 0 :=
-  Nat.cast_ne_zero.2 <| ne_of_gt <| lt_trans Nat.one_pos h.prop
+@[simp] lemma ofNat_ne_zero (n : ℕ) [n.AtLeastTwo] : (no_index (ofNat n) : R) ≠ 0 :=
+  Nat.cast_ne_zero.2 (NeZero.ne n)
 
 @[simp] lemma zero_ne_ofNat (n : ℕ) [n.AtLeastTwo] : 0 ≠ (no_index (ofNat n) : R) :=
   (ofNat_ne_zero n).symm
 
-@[simp] lemma ofNat_ne_one (n : ℕ) [h : n.AtLeastTwo] : (no_index (ofNat n) : R) ≠ 1 := by
-  rw [← Nat.cast_eq_ofNat, ← @Nat.cast_one R, Ne.def, Nat.cast_inj]
-  exact ne_of_gt h.prop
+@[simp] lemma ofNat_ne_one (n : ℕ) [n.AtLeastTwo] : (no_index (ofNat n) : R) ≠ 1 :=
+  Nat.cast_ne_one.2 (Nat.AtLeastTwo.ne_one)
 
 @[simp] lemma one_ne_ofNat (n : ℕ) [n.AtLeastTwo] : (1 : R) ≠ no_index (ofNat n) :=
   (ofNat_ne_one n).symm

d6aae1bc

chore: refactor of Algebra/Group/Defs to reduce imports (#9606)

We are not that far from the point that Algebra/Group/Defs depends on nothing significant besides simps and to_additive.

This removes from Mathlib.Algebra.Group.Defs the dependencies on

Mathlib.Tactic.Basic (which is a grab-bag of random stuff)
Mathlib.Init.Algebra.Classes (which is ancient and half-baked)
Mathlib.Logic.Function.Basic (not particularly important, but it is barely used in this file)

The goal is to avoid all unnecessary imports to set up the definitions of basic algebraic structures.

We also separate out Mathlib.Tactic.TypeStar and Mathlib.Tactic.Lemma as prerequisites to Mathlib.Tactic.Basic, but which can be imported separately when the rest of Mathlib.Tactic.Basic is not needed.

Co-authored-by: Scott Morrison <scott.morrison@gmail.com> Co-authored-by: Yaël Dillies <yael.dillies@gmail.com>

45df8238

Diff

@@ -7,6 +7,7 @@ import Mathlib.Init.Data.Nat.Lemmas
 import Mathlib.Data.Int.Cast.Defs
 import Mathlib.Tactic.Cases
 import Mathlib.Algebra.NeZero
+import Mathlib.Logic.Function.Basic
 
 #align_import algebra.char_zero.defs from "leanprover-community/mathlib"@"d6aae1bcbd04b8de2022b9b83a5b5b10e10c777d"

d6aae1bc

chore: space after ← (#8178)

Co-authored-by: Moritz Firsching <firsching@google.com>

5fb9beab

Diff

@@ -132,7 +132,7 @@ instance charZero {M} {n : ℕ} [NeZero n] [AddMonoidWithOne M] [CharZero M] : N
 
 instance charZero_one {M} [AddMonoidWithOne M] [CharZero M] : NeZero (1 : M) where
   out := by
-    rw [←Nat.cast_one, Nat.cast_ne_zero]
+    rw [← Nat.cast_one, Nat.cast_ne_zero]
     trivial
 
 instance charZero_ofNat {M} {n : ℕ} [n.AtLeastTwo] [AddMonoidWithOne M] [CharZero M] :

d6aae1bc

chore: bump Std (#8403)

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

a977ca14

Diff

@@ -5,7 +5,6 @@ Authors: Mario Carneiro
 -/
 import Mathlib.Init.Data.Nat.Lemmas
 import Mathlib.Data.Int.Cast.Defs
-import Mathlib.Tactic.NormCast.Tactic
 import Mathlib.Tactic.Cases
 import Mathlib.Algebra.NeZero

d6aae1bc

chore(PartENat): golf and improve ofNat support (#8002)

This PR adds simp lemmas for OfNat.ofNat n : PartENat, 0 : PartENat, and 1 : PartENat in every place where there was a simp lemma for ((n : ℕ) : PartENat). This is necessary for simp confluence in the presence of lemmas such as Nat.cast_ofNat. In addition, instances for CharZero and ZeroLEOneClass are provided so that the lemmas from Data/Nat/Cast/Order.lean will apply, golfing some proofs.

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

8e84de5e

Diff

@@ -131,6 +131,11 @@ instance charZero {M} {n : ℕ} [NeZero n] [AddMonoidWithOne M] [CharZero M] : N
   ⟨Nat.cast_ne_zero.mpr out⟩
 #align ne_zero.char_zero NeZero.charZero
 
+instance charZero_one {M} [AddMonoidWithOne M] [CharZero M] : NeZero (1 : M) where
+  out := by
+    rw [←Nat.cast_one, Nat.cast_ne_zero]
+    trivial
+
 instance charZero_ofNat {M} {n : ℕ} [n.AtLeastTwo] [AddMonoidWithOne M] [CharZero M] :
     NeZero (OfNat.ofNat n : M) :=
   ⟨OfNat.ofNat_ne_zero n⟩

d6aae1bc

chore: cleanup Init/Data/Nat/Lemmas (#7704)

~~I'll upstream Nat.find shortly~~, just cleaning up the cruft here first.

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

5744925e

Diff

@@ -6,6 +6,7 @@ Authors: Mario Carneiro
 import Mathlib.Init.Data.Nat.Lemmas
 import Mathlib.Data.Int.Cast.Defs
 import Mathlib.Tactic.NormCast.Tactic
+import Mathlib.Tactic.Cases
 import Mathlib.Algebra.NeZero
 
 #align_import algebra.char_zero.defs from "leanprover-community/mathlib"@"d6aae1bcbd04b8de2022b9b83a5b5b10e10c777d"

d6aae1bc

chore: cleanup in Mathlib.Init (#6977)

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

8f46576d

Diff

@@ -3,6 +3,7 @@ Copyright (c) 2014 Mario Carneiro. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Mario Carneiro
 -/
+import Mathlib.Init.Data.Nat.Lemmas
 import Mathlib.Data.Int.Cast.Defs
 import Mathlib.Tactic.NormCast.Tactic
 import Mathlib.Algebra.NeZero

d6aae1bc

chore: separate NeZero dependency from Nat/Cast/Defs (#6955)

I'm trying to remove any extraneous material from the core definitions in the algebraic hierarchy that are used in tactics.

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

9a51c25f

Diff

@@ -5,6 +5,7 @@ Authors: Mario Carneiro
 -/
 import Mathlib.Data.Int.Cast.Defs
 import Mathlib.Tactic.NormCast.Tactic
+import Mathlib.Algebra.NeZero
 
 #align_import algebra.char_zero.defs from "leanprover-community/mathlib"@"d6aae1bcbd04b8de2022b9b83a5b5b10e10c777d"

d6aae1bc

chore: fix doc-strings about (c vs C)ounterexamples (#6691)

This PR just touches doc-strings. It fixes capitalization issues involving Counterexamples and adds a missing line-break for better display.

0b511e95

Diff

@@ -31,13 +31,14 @@ set_option autoImplicit true
 
 /-- Typeclass for monoids with characteristic zero.
   (This is usually stated on fields but it makes sense for any additive monoid with 1.)
+
 *Warning*: for a semiring `R`, `CharZero R` and `CharP R 0` need not coincide.
 * `CharZero R` requires an injection `ℕ ↪ R`;
 * `CharP R 0` asks that only `0 : ℕ` maps to `0 : R` under the map `ℕ → R`.
 For instance, endowing `{0, 1}` with addition given by `max` (i.e. `1` is absorbing), shows that
 `CharZero {0, 1}` does not hold and yet `CharP {0, 1} 0` does.
-This example is formalized in `counterexamples/char_p_zero_ne_char_zero`.
- -/
+This example is formalized in `Counterexamples/CharPZeroNeCharZero.lean`.
+-/
 class CharZero (R) [AddMonoidWithOne R] : Prop where
   /-- An additive monoid with one has characteristic zero if the canonical map `ℕ → R` is
   injective. -/

d6aae1bc

fix: disable autoImplicit globally (#6528)

Autoimplicits are highly controversial and also defeat the performance-improving work in #6474.

The intent of this PR is to make autoImplicit opt-in on a per-file basis, by disabling it in the lakefile and enabling it again with set_option autoImplicit true in the few files that rely on it.

That also keeps this PR small, as opposed to attempting to "fix" files to not need it any more.

I claim that many of the uses of autoImplicit in these files are accidental; situations such as:

Assuming variables are in scope, but pasting the lemma in the wrong section
Pasting in a lemma from a scratch file without checking to see if the variable names are consistent with the rest of the file
Making a copy-paste error between lemmas and forgetting to add an explicit arguments.

Having set_option autoImplicit false as the default prevents these types of mistake being made in the 90% of files where autoImplicits are not used at all, and causes them to be caught by CI during review.

I think there were various points during the port where we encouraged porters to delete the universes u v lines; I think having autoparams for universe variables only would cover a lot of the cases we actually use them, while avoiding any real shortcomings.

A Zulip poll (after combining overlapping votes accordingly) was in favor of this change with 5:5:18 as the no:dontcare:yes vote ratio.

While this PR was being reviewed, a handful of files gained some more likely-accidental autoImplicits. In these places, set_option autoImplicit true has been placed locally within a section, rather than at the top of the file.

0c24f831

Diff

@@ -27,6 +27,8 @@ from the natural numbers into it is injective.
 * Unify with `CharP` (possibly using an out-parameter)
 -/
 
+set_option autoImplicit true
+
 /-- Typeclass for monoids with characteristic zero.
   (This is usually stated on fields but it makes sense for any additive monoid with 1.)
 *Warning*: for a semiring `R`, `CharZero R` and `CharP R 0` need not coincide.

d6aae1bc

chore: script to replace headers with #align_import statements (#5979)

depends on: #5966

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

89aa3a3b

Diff

@@ -2,15 +2,12 @@
 Copyright (c) 2014 Mario Carneiro. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Mario Carneiro
-
-! This file was ported from Lean 3 source module algebra.char_zero.defs
-! leanprover-community/mathlib commit d6aae1bcbd04b8de2022b9b83a5b5b10e10c777d
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathlib.Data.Int.Cast.Defs
 import Mathlib.Tactic.NormCast.Tactic
 
+#align_import algebra.char_zero.defs from "leanprover-community/mathlib"@"d6aae1bcbd04b8de2022b9b83a5b5b10e10c777d"
+
 /-!
 
 # Characteristic zero

d6aae1bc

chore: bump to nightly-2023-07-01 (#5409)

depends on: https://github.com/leanprover/std4/pull/163
depends on: #5584
depends on: #5715
depends on: #5729
depends on: https://github.com/leanprover/std4/pull/173

Co-authored-by: Komyyy <pol_tta@outlook.jp> Co-authored-by: Scott Morrison <scott.morrison@gmail.com> Co-authored-by: Scott Morrison <scott.morrison@anu.edu.au> Co-authored-by: Ruben Van de Velde <65514131+Ruben-VandeVelde@users.noreply.github.com> Co-authored-by: Mario Carneiro <di.gama@gmail.com>

906f7221

Diff

@@ -103,21 +103,21 @@ namespace OfNat
 
 variable [AddMonoidWithOne R] [CharZero R]
 
-@[simp] lemma ofNat_ne_zero (n : ℕ) [h : n.AtLeastTwo] : (ofNat n : R) ≠ 0 :=
+@[simp] lemma ofNat_ne_zero (n : ℕ) [h : n.AtLeastTwo] : (no_index (ofNat n) : R) ≠ 0 :=
   Nat.cast_ne_zero.2 <| ne_of_gt <| lt_trans Nat.one_pos h.prop
 
-@[simp] lemma zero_ne_ofNat (n : ℕ) [n.AtLeastTwo] : 0 ≠ (ofNat n : R) :=
+@[simp] lemma zero_ne_ofNat (n : ℕ) [n.AtLeastTwo] : 0 ≠ (no_index (ofNat n) : R) :=
   (ofNat_ne_zero n).symm
 
-@[simp] lemma ofNat_ne_one (n : ℕ) [h : n.AtLeastTwo] : (ofNat n : R) ≠ 1 := by
+@[simp] lemma ofNat_ne_one (n : ℕ) [h : n.AtLeastTwo] : (no_index (ofNat n) : R) ≠ 1 := by
   rw [← Nat.cast_eq_ofNat, ← @Nat.cast_one R, Ne.def, Nat.cast_inj]
   exact ne_of_gt h.prop
 
-@[simp] lemma one_ne_ofNat (n : ℕ) [n.AtLeastTwo] : (1 : R) ≠ ofNat n :=
+@[simp] lemma one_ne_ofNat (n : ℕ) [n.AtLeastTwo] : (1 : R) ≠ no_index (ofNat n) :=
   (ofNat_ne_one n).symm
 
 @[simp] lemma ofNat_eq_ofNat {m n : ℕ} [m.AtLeastTwo] [n.AtLeastTwo] :
-    (ofNat m : R) = ofNat n ↔ (ofNat m : ℕ) = ofNat n :=
+    (no_index (ofNat m) : R) = no_index (ofNat n) ↔ (ofNat m : ℕ) = ofNat n :=
   Nat.cast_inj
 
 end OfNat

d6aae1bc

feat: simplify equality of nat literals (#2389)

If M has characteristic zero, then we simplify, e.g., (2 : M) = 10 to (2 : ℕ) = 10.

5c82b503

Diff

@@ -40,7 +40,7 @@ For instance, endowing `{0, 1}` with addition given by `max` (i.e. `1` is absorb
 This example is formalized in `counterexamples/char_p_zero_ne_char_zero`.
  -/
 class CharZero (R) [AddMonoidWithOne R] : Prop where
-  /-- An additive monoid with one has charateristic zero if the canonical map `ℕ → R` is
+  /-- An additive monoid with one has characteristic zero if the canonical map `ℕ → R` is
   injective. -/
   cast_injective : Function.Injective (Nat.cast : ℕ → R)
 #align char_zero CharZero
@@ -99,10 +99,37 @@ theorem cast_ne_one {n : ℕ} : (n : R) ≠ 1 ↔ n ≠ 1 :=
 
 end Nat
 
+namespace OfNat
+
+variable [AddMonoidWithOne R] [CharZero R]
+
+@[simp] lemma ofNat_ne_zero (n : ℕ) [h : n.AtLeastTwo] : (ofNat n : R) ≠ 0 :=
+  Nat.cast_ne_zero.2 <| ne_of_gt <| lt_trans Nat.one_pos h.prop
+
+@[simp] lemma zero_ne_ofNat (n : ℕ) [n.AtLeastTwo] : 0 ≠ (ofNat n : R) :=
+  (ofNat_ne_zero n).symm
+
+@[simp] lemma ofNat_ne_one (n : ℕ) [h : n.AtLeastTwo] : (ofNat n : R) ≠ 1 := by
+  rw [← Nat.cast_eq_ofNat, ← @Nat.cast_one R, Ne.def, Nat.cast_inj]
+  exact ne_of_gt h.prop
+
+@[simp] lemma one_ne_ofNat (n : ℕ) [n.AtLeastTwo] : (1 : R) ≠ ofNat n :=
+  (ofNat_ne_one n).symm
+
+@[simp] lemma ofNat_eq_ofNat {m n : ℕ} [m.AtLeastTwo] [n.AtLeastTwo] :
+    (ofNat m : R) = ofNat n ↔ (ofNat m : ℕ) = ofNat n :=
+  Nat.cast_inj
+
+end OfNat
+
 namespace NeZero
 
 instance charZero {M} {n : ℕ} [NeZero n] [AddMonoidWithOne M] [CharZero M] : NeZero (n : M) :=
   ⟨Nat.cast_ne_zero.mpr out⟩
 #align ne_zero.char_zero NeZero.charZero
 
+instance charZero_ofNat {M} {n : ℕ} [n.AtLeastTwo] [AddMonoidWithOne M] [CharZero M] :
+    NeZero (OfNat.ofNat n : M) :=
+  ⟨OfNat.ofNat_ne_zero n⟩
+
 end NeZero

d6aae1bc

chore: add source headers to ported theory files (#1094)

The script used to do this is included. The yaml file was obtained from https://raw.githubusercontent.com/wiki/leanprover-community/mathlib/mathlib4-port-status.md

f168625e

Diff

@@ -2,6 +2,11 @@
 Copyright (c) 2014 Mario Carneiro. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Mario Carneiro
+
+! This file was ported from Lean 3 source module algebra.char_zero.defs
+! leanprover-community/mathlib commit d6aae1bcbd04b8de2022b9b83a5b5b10e10c777d
+! Please do not edit these lines, except to modify the commit id
+! if you have ported upstream changes.
 -/
 import Mathlib.Data.Int.Cast.Defs
 import Mathlib.Tactic.NormCast.Tactic

`algebra.char_zero.defs` ⟷ `Mathlib.Algebra.CharZero.Defs`

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 5

algebra.char_zero.defs ⟷ Mathlib.Algebra.CharZero.Defs

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 5

`algebra.char_zero.defs` ⟷ `Mathlib.Algebra.CharZero.Defs`