deprecated.ring ⟷ Mathlib.Deprecated.Ring

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

@@ -37,10 +37,10 @@ universe u v w
 variable {α : Type u}
 
 #print IsSemiringHom /-
-/- ./././Mathport/Syntax/Translate/Command.lean:404:30: infer kinds are unsupported in Lean 4: #[`map_zero] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:404:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:404:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:404:30: infer kinds are unsupported in Lean 4: #[`map_hMul] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:400:30: infer kinds are unsupported in Lean 4: #[`map_zero] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:400:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:400:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:400:30: infer kinds are unsupported in Lean 4: #[`map_hMul] [] -/
 /-- Predicate for semiring homomorphisms (deprecated -- use the bundled `ring_hom` version). -/
 structure IsSemiringHom {α : Type u} {β : Type v} [Semiring α] [Semiring β] (f : α → β) : Prop where
   map_zero : f 0 = 0
@@ -90,9 +90,9 @@ theorem to_isMonoidHom (hf : IsSemiringHom f) : IsMonoidHom f :=
 end IsSemiringHom
 
 #print IsRingHom /-
-/- ./././Mathport/Syntax/Translate/Command.lean:404:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:404:30: infer kinds are unsupported in Lean 4: #[`map_hMul] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:404:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:400:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:400:30: infer kinds are unsupported in Lean 4: #[`map_hMul] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:400:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
 /-- Predicate for ring homomorphisms (deprecated -- use the bundled `ring_hom` version). -/
 structure IsRingHom {α : Type u} {β : Type v} [Ring α] [Ring β] (f : α → β) : Prop where
   map_one : f 1 = 1

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

@@ -37,10 +37,10 @@ universe u v w
 variable {α : Type u}
 
 #print IsSemiringHom /-
-/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_zero] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_hMul] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:404:30: infer kinds are unsupported in Lean 4: #[`map_zero] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:404:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:404:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:404:30: infer kinds are unsupported in Lean 4: #[`map_hMul] [] -/
 /-- Predicate for semiring homomorphisms (deprecated -- use the bundled `ring_hom` version). -/
 structure IsSemiringHom {α : Type u} {β : Type v} [Semiring α] [Semiring β] (f : α → β) : Prop where
   map_zero : f 0 = 0
@@ -90,9 +90,9 @@ theorem to_isMonoidHom (hf : IsSemiringHom f) : IsMonoidHom f :=
 end IsSemiringHom
 
 #print IsRingHom /-
-/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_hMul] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:404:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:404:30: infer kinds are unsupported in Lean 4: #[`map_hMul] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:404:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
 /-- Predicate for ring homomorphisms (deprecated -- use the bundled `ring_hom` version). -/
 structure IsRingHom {α : Type u} {β : Type v} [Ring α] [Ring β] (f : α → β) : Prop where
   map_one : f 1 = 1

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

@@ -3,7 +3,7 @@ Copyright (c) 2020 Mario Carneiro. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Mario Carneiro
 -/
-import Mathbin.Deprecated.Group
+import Deprecated.Group
 
 #align_import deprecated.ring from "leanprover-community/mathlib"@"10708587e81b68c763fcdb7505f279d52e569768"
 
@@ -37,10 +37,10 @@ universe u v w
 variable {α : Type u}
 
 #print IsSemiringHom /-
-/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_zero] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_hMul] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_zero] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_hMul] [] -/
 /-- Predicate for semiring homomorphisms (deprecated -- use the bundled `ring_hom` version). -/
 structure IsSemiringHom {α : Type u} {β : Type v} [Semiring α] [Semiring β] (f : α → β) : Prop where
   map_zero : f 0 = 0
@@ -90,9 +90,9 @@ theorem to_isMonoidHom (hf : IsSemiringHom f) : IsMonoidHom f :=
 end IsSemiringHom
 
 #print IsRingHom /-
-/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_hMul] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_hMul] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
 /-- Predicate for ring homomorphisms (deprecated -- use the bundled `ring_hom` version). -/
 structure IsRingHom {α : Type u} {β : Type v} [Ring α] [Ring β] (f : α → β) : Prop where
   map_one : f 1 = 1

mathlib commit https://github.com/leanprover-community/mathlib/commit/32a7e535287f9c73f2e4d2aef306a39190f0b504

@@ -40,13 +40,13 @@ variable {α : Type u}
 /- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_zero] [] -/
 /- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
 /- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_mul] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_hMul] [] -/
 /-- Predicate for semiring homomorphisms (deprecated -- use the bundled `ring_hom` version). -/
 structure IsSemiringHom {α : Type u} {β : Type v} [Semiring α] [Semiring β] (f : α → β) : Prop where
   map_zero : f 0 = 0
   map_one : f 1 = 1
   map_add : ∀ {x y}, f (x + y) = f x + f y
-  map_mul : ∀ {x y}, f (x * y) = f x * f y
+  map_hMul : ∀ {x y}, f (x * y) = f x * f y
 #align is_semiring_hom IsSemiringHom
 -/
 
@@ -69,7 +69,7 @@ theorem comp (hf : IsSemiringHom f) {γ} [Semiring γ] {g : β → γ} (hg : IsS
   { map_zero := by simpa [map_zero hf] using map_zero hg
     map_one := by simpa [map_one hf] using map_one hg
     map_add := fun x y => by simp [map_add hf, map_add hg]
-    map_mul := fun x y => by simp [map_mul hf, map_mul hg] }
+    map_hMul := fun x y => by simp [map_mul hf, map_mul hg] }
 #align is_semiring_hom.comp IsSemiringHom.comp
 -/
 
@@ -91,12 +91,12 @@ end IsSemiringHom
 
 #print IsRingHom /-
 /- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_mul] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_hMul] [] -/
 /- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
 /-- Predicate for ring homomorphisms (deprecated -- use the bundled `ring_hom` version). -/
 structure IsRingHom {α : Type u} {β : Type v} [Ring α] [Ring β] (f : α → β) : Prop where
   map_one : f 1 = 1
-  map_mul : ∀ {x y}, f (x * y) = f x * f y
+  map_hMul : ∀ {x y}, f (x * y) = f x * f y
   map_add : ∀ {x y}, f (x + y) = f x + f y
 #align is_ring_hom IsRingHom
 -/
@@ -150,7 +150,7 @@ theorem id : IsRingHom (@id α) := by refine' { .. } <;> intros <;> rfl
 /-- The composition of two ring homomorphisms is a ring homomorphism. -/
 theorem comp (hf : IsRingHom f) {γ} [Ring γ] {g : β → γ} (hg : IsRingHom g) : IsRingHom (g ∘ f) :=
   { map_add := fun x y => by simp [map_add hf] <;> rw [map_add hg] <;> rfl
-    map_mul := fun x y => by simp [map_mul hf] <;> rw [map_mul hg] <;> rfl
+    map_hMul := fun x y => by simp [map_mul hf] <;> rw [map_mul hg] <;> rfl
     map_one := by simp [map_one hf] <;> exact map_one hg }
 #align is_ring_hom.comp IsRingHom.comp
 -/
@@ -195,7 +195,7 @@ theorem to_isSemiringHom (f : α →+* β) : IsSemiringHom f :=
   { map_zero := f.map_zero
     map_one := f.map_one
     map_add := f.map_add
-    map_mul := f.map_mul }
+    map_hMul := f.map_hMul }
 #align ring_hom.to_is_semiring_hom RingHom.to_isSemiringHom
 -/
 

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

@@ -2,14 +2,11 @@
 Copyright (c) 2020 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 deprecated.ring
-! leanprover-community/mathlib commit 10708587e81b68c763fcdb7505f279d52e569768
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathbin.Deprecated.Group
 
+#align_import deprecated.ring from "leanprover-community/mathlib"@"10708587e81b68c763fcdb7505f279d52e569768"
+
 /-!
 # Unbundled semiring and ring homomorphisms (deprecated)
 

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

@@ -40,10 +40,10 @@ universe u v w
 variable {α : Type u}
 
 #print IsSemiringHom /-
-/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_zero] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_mul] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_zero] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_mul] [] -/
 /-- Predicate for semiring homomorphisms (deprecated -- use the bundled `ring_hom` version). -/
 structure IsSemiringHom {α : Type u} {β : Type v} [Semiring α] [Semiring β] (f : α → β) : Prop where
   map_zero : f 0 = 0
@@ -65,6 +65,7 @@ theorem id : IsSemiringHom (@id α) := by refine' { .. } <;> intros <;> rfl
 #align is_semiring_hom.id IsSemiringHom.id
 -/
 
+#print IsSemiringHom.comp /-
 /-- The composition of two semiring homomorphisms is a semiring homomorphism. -/
 theorem comp (hf : IsSemiringHom f) {γ} [Semiring γ] {g : β → γ} (hg : IsSemiringHom g) :
     IsSemiringHom (g ∘ f) :=
@@ -73,6 +74,7 @@ theorem comp (hf : IsSemiringHom f) {γ} [Semiring γ] {g : β → γ} (hg : IsS
     map_add := fun x y => by simp [map_add hf, map_add hg]
     map_mul := fun x y => by simp [map_mul hf, map_mul hg] }
 #align is_semiring_hom.comp IsSemiringHom.comp
+-/
 
 #print IsSemiringHom.to_isAddMonoidHom /-
 /-- A semiring homomorphism is an additive monoid homomorphism. -/
@@ -91,9 +93,9 @@ theorem to_isMonoidHom (hf : IsSemiringHom f) : IsMonoidHom f :=
 end IsSemiringHom
 
 #print IsRingHom /-
-/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_mul] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_mul] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
 /-- Predicate for ring homomorphisms (deprecated -- use the bundled `ring_hom` version). -/
 structure IsRingHom {α : Type u} {β : Type v} [Ring α] [Ring β] (f : α → β) : Prop where
   map_one : f 1 = 1
@@ -115,24 +117,30 @@ theorem of_semiring {f : α → β} (H : IsSemiringHom f) : IsRingHom f :=
 
 variable {f : α → β} (hf : IsRingHom f) {x y : α}
 
+#print IsRingHom.map_zero /-
 /-- Ring homomorphisms map zero to zero. -/
 theorem map_zero (hf : IsRingHom f) : f 0 = 0 :=
   calc
     f 0 = f (0 + 0) - f 0 := by rw [hf.map_add] <;> simp
     _ = 0 := by simp
 #align is_ring_hom.map_zero IsRingHom.map_zero
+-/
 
+#print IsRingHom.map_neg /-
 /-- Ring homomorphisms preserve additive inverses. -/
 theorem map_neg (hf : IsRingHom f) : f (-x) = -f x :=
   calc
     f (-x) = f (-x + x) - f x := by rw [hf.map_add] <;> simp
     _ = -f x := by simp [hf.map_zero]
 #align is_ring_hom.map_neg IsRingHom.map_neg
+-/
 
+#print IsRingHom.map_sub /-
 /-- Ring homomorphisms preserve subtraction. -/
 theorem map_sub (hf : IsRingHom f) : f (x - y) = f x - f y := by
   simp [sub_eq_add_neg, hf.map_add, hf.map_neg]
 #align is_ring_hom.map_sub IsRingHom.map_sub
+-/
 
 #print IsRingHom.id /-
 /-- The identity map is a ring homomorphism. -/
@@ -140,6 +148,7 @@ theorem id : IsRingHom (@id α) := by refine' { .. } <;> intros <;> rfl
 #align is_ring_hom.id IsRingHom.id
 -/
 
+#print IsRingHom.comp /-
 -- see Note [no instance on morphisms]
 /-- The composition of two ring homomorphisms is a ring homomorphism. -/
 theorem comp (hf : IsRingHom f) {γ} [Ring γ] {g : β → γ} (hg : IsRingHom g) : IsRingHom (g ∘ f) :=
@@ -147,6 +156,7 @@ theorem comp (hf : IsRingHom f) {γ} [Ring γ] {g : β → γ} (hg : IsRingHom g
     map_mul := fun x y => by simp [map_mul hf] <;> rw [map_mul hg] <;> rfl
     map_one := by simp [map_one hf] <;> exact map_one hg }
 #align is_ring_hom.comp IsRingHom.comp
+-/
 
 #print IsRingHom.to_isSemiringHom /-
 /-- A ring homomorphism is also a semiring homomorphism. -/
@@ -155,9 +165,11 @@ theorem to_isSemiringHom (hf : IsRingHom f) : IsSemiringHom f :=
 #align is_ring_hom.to_is_semiring_hom IsRingHom.to_isSemiringHom
 -/
 
+#print IsRingHom.to_isAddGroupHom /-
 theorem to_isAddGroupHom (hf : IsRingHom f) : IsAddGroupHom f :=
   { map_add := fun _ _ => hf.map_add }
 #align is_ring_hom.to_is_add_group_hom IsRingHom.to_isAddGroupHom
+-/
 
 end IsRingHom
 
@@ -167,8 +179,6 @@ namespace RingHom
 
 section
 
-include rα rβ
-
 #print RingHom.of /-
 /-- Interpret `f : α → β` with `is_semiring_hom f` as a ring homomorphism. -/
 def of {f : α → β} (hf : IsSemiringHom f) : α →+* β :=
@@ -176,23 +186,29 @@ def of {f : α → β} (hf : IsSemiringHom f) : α →+* β :=
 #align ring_hom.of RingHom.of
 -/
 
+#print RingHom.coe_of /-
 @[simp]
 theorem coe_of {f : α → β} (hf : IsSemiringHom f) : ⇑(of hf) = f :=
   rfl
 #align ring_hom.coe_of RingHom.coe_of
+-/
 
+#print RingHom.to_isSemiringHom /-
 theorem to_isSemiringHom (f : α →+* β) : IsSemiringHom f :=
   { map_zero := f.map_zero
     map_one := f.map_one
     map_add := f.map_add
     map_mul := f.map_mul }
 #align ring_hom.to_is_semiring_hom RingHom.to_isSemiringHom
+-/
 
 end
 
+#print RingHom.to_isRingHom /-
 theorem to_isRingHom {α γ} [Ring α] [Ring γ] (g : α →+* γ) : IsRingHom g :=
   IsRingHom.of_semiring g.to_isSemiringHom
 #align ring_hom.to_is_ring_hom RingHom.to_isRingHom
+-/
 
 end RingHom
 

mathlib commit https://github.com/leanprover-community/mathlib/commit/7e5137f579de09a059a5ce98f364a04e221aabf0

@@ -120,7 +120,6 @@ theorem map_zero (hf : IsRingHom f) : f 0 = 0 :=
   calc
     f 0 = f (0 + 0) - f 0 := by rw [hf.map_add] <;> simp
     _ = 0 := by simp
-    
 #align is_ring_hom.map_zero IsRingHom.map_zero
 
 /-- Ring homomorphisms preserve additive inverses. -/
@@ -128,7 +127,6 @@ theorem map_neg (hf : IsRingHom f) : f (-x) = -f x :=
   calc
     f (-x) = f (-x + x) - f x := by rw [hf.map_add] <;> simp
     _ = -f x := by simp [hf.map_zero]
-    
 #align is_ring_hom.map_neg IsRingHom.map_neg
 
 /-- Ring homomorphisms preserve subtraction. -/

mathlib commit https://github.com/leanprover-community/mathlib/commit/5f25c089cb34db4db112556f23c50d12da81b297

@@ -40,10 +40,10 @@ universe u v w
 variable {α : Type u}
 
 #print IsSemiringHom /-
-/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_zero] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_mul] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_zero] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_mul] [] -/
 /-- Predicate for semiring homomorphisms (deprecated -- use the bundled `ring_hom` version). -/
 structure IsSemiringHom {α : Type u} {β : Type v} [Semiring α] [Semiring β] (f : α → β) : Prop where
   map_zero : f 0 = 0
@@ -91,9 +91,9 @@ theorem to_isMonoidHom (hf : IsSemiringHom f) : IsMonoidHom f :=
 end IsSemiringHom
 
 #print IsRingHom /-
-/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_mul] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_mul] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:394:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
 /-- Predicate for ring homomorphisms (deprecated -- use the bundled `ring_hom` version). -/
 structure IsRingHom {α : Type u} {β : Type v} [Ring α] [Ring β] (f : α → β) : Prop where
   map_one : f 1 = 1

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

@@ -65,12 +65,6 @@ theorem id : IsSemiringHom (@id α) := by refine' { .. } <;> intros <;> rfl
 #align is_semiring_hom.id IsSemiringHom.id
 -/
 
-/- warning: is_semiring_hom.comp -> IsSemiringHom.comp is a dubious translation:
-lean 3 declaration is
-  forall {α : Type.{u1}} {β : Type.{u2}} [_inst_1 : Semiring.{u1} α] [_inst_2 : Semiring.{u2} β] {f : α -> β}, (IsSemiringHom.{u1, u2} α β _inst_1 _inst_2 f) -> (forall {γ : Type.{u3}} [_inst_3 : Semiring.{u3} γ] {g : β -> γ}, (IsSemiringHom.{u2, u3} β γ _inst_2 _inst_3 g) -> (IsSemiringHom.{u1, u3} α γ _inst_1 _inst_3 (Function.comp.{succ u1, succ u2, succ u3} α β γ g f)))
-but is expected to have type
-  forall {α : Type.{u2}} {β : Type.{u3}} [_inst_1 : Semiring.{u2} α] [_inst_2 : Semiring.{u3} β] {f : α -> β}, (IsSemiringHom.{u2, u3} α β _inst_1 _inst_2 f) -> (forall {γ : Type.{u1}} [_inst_3 : Semiring.{u1} γ] {g : β -> γ}, (IsSemiringHom.{u3, u1} β γ _inst_2 _inst_3 g) -> (IsSemiringHom.{u2, u1} α γ _inst_1 _inst_3 (Function.comp.{succ u2, succ u3, succ u1} α β γ g f)))
-Case conversion may be inaccurate. Consider using '#align is_semiring_hom.comp IsSemiringHom.compₓ'. -/
 /-- The composition of two semiring homomorphisms is a semiring homomorphism. -/
 theorem comp (hf : IsSemiringHom f) {γ} [Semiring γ] {g : β → γ} (hg : IsSemiringHom g) :
     IsSemiringHom (g ∘ f) :=
@@ -121,12 +115,6 @@ theorem of_semiring {f : α → β} (H : IsSemiringHom f) : IsRingHom f :=
 
 variable {f : α → β} (hf : IsRingHom f) {x y : α}
 
-/- warning: is_ring_hom.map_zero -> IsRingHom.map_zero is a dubious translation:
-lean 3 declaration is
-  forall {α : Type.{u1}} {β : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} β] {f : α -> β}, (IsRingHom.{u1, u2} α β _inst_1 _inst_2 f) -> (Eq.{succ u2} β (f (OfNat.ofNat.{u1} α 0 (OfNat.mk.{u1} α 0 (Zero.zero.{u1} α (MulZeroClass.toHasZero.{u1} α (NonUnitalNonAssocSemiring.toMulZeroClass.{u1} α (NonUnitalNonAssocRing.toNonUnitalNonAssocSemiring.{u1} α (NonAssocRing.toNonUnitalNonAssocRing.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1))))))))) (OfNat.ofNat.{u2} β 0 (OfNat.mk.{u2} β 0 (Zero.zero.{u2} β (MulZeroClass.toHasZero.{u2} β (NonUnitalNonAssocSemiring.toMulZeroClass.{u2} β (NonUnitalNonAssocRing.toNonUnitalNonAssocSemiring.{u2} β (NonAssocRing.toNonUnitalNonAssocRing.{u2} β (Ring.toNonAssocRing.{u2} β _inst_2)))))))))
-but is expected to have type
-  forall {α : Type.{u1}} {β : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} β] {f : α -> β}, (IsRingHom.{u1, u2} α β _inst_1 _inst_2 f) -> (Eq.{succ u2} β (f (OfNat.ofNat.{u1} α 0 (Zero.toOfNat0.{u1} α (MonoidWithZero.toZero.{u1} α (Semiring.toMonoidWithZero.{u1} α (Ring.toSemiring.{u1} α _inst_1)))))) (OfNat.ofNat.{u2} β 0 (Zero.toOfNat0.{u2} β (MonoidWithZero.toZero.{u2} β (Semiring.toMonoidWithZero.{u2} β (Ring.toSemiring.{u2} β _inst_2))))))
-Case conversion may be inaccurate. Consider using '#align is_ring_hom.map_zero IsRingHom.map_zeroₓ'. -/
 /-- Ring homomorphisms map zero to zero. -/
 theorem map_zero (hf : IsRingHom f) : f 0 = 0 :=
   calc
@@ -135,12 +123,6 @@ theorem map_zero (hf : IsRingHom f) : f 0 = 0 :=
     
 #align is_ring_hom.map_zero IsRingHom.map_zero
 
-/- warning: is_ring_hom.map_neg -> IsRingHom.map_neg is a dubious translation:
-lean 3 declaration is
-  forall {α : Type.{u1}} {β : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} β] {f : α -> β} {x : α}, (IsRingHom.{u1, u2} α β _inst_1 _inst_2 f) -> (Eq.{succ u2} β (f (Neg.neg.{u1} α (SubNegMonoid.toHasNeg.{u1} α (AddGroup.toSubNegMonoid.{u1} α (AddGroupWithOne.toAddGroup.{u1} α (AddCommGroupWithOne.toAddGroupWithOne.{u1} α (Ring.toAddCommGroupWithOne.{u1} α _inst_1))))) x)) (Neg.neg.{u2} β (SubNegMonoid.toHasNeg.{u2} β (AddGroup.toSubNegMonoid.{u2} β (AddGroupWithOne.toAddGroup.{u2} β (AddCommGroupWithOne.toAddGroupWithOne.{u2} β (Ring.toAddCommGroupWithOne.{u2} β _inst_2))))) (f x)))
-but is expected to have type
-  forall {α : Type.{u1}} {β : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} β] {f : α -> β} {x : α}, (IsRingHom.{u1, u2} α β _inst_1 _inst_2 f) -> (Eq.{succ u2} β (f (Neg.neg.{u1} α (Ring.toNeg.{u1} α _inst_1) x)) (Neg.neg.{u2} β (Ring.toNeg.{u2} β _inst_2) (f x)))
-Case conversion may be inaccurate. Consider using '#align is_ring_hom.map_neg IsRingHom.map_negₓ'. -/
 /-- Ring homomorphisms preserve additive inverses. -/
 theorem map_neg (hf : IsRingHom f) : f (-x) = -f x :=
   calc
@@ -149,12 +131,6 @@ theorem map_neg (hf : IsRingHom f) : f (-x) = -f x :=
     
 #align is_ring_hom.map_neg IsRingHom.map_neg
 
-/- warning: is_ring_hom.map_sub -> IsRingHom.map_sub is a dubious translation:
-lean 3 declaration is
-  forall {α : Type.{u1}} {β : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} β] {f : α -> β} {x : α} {y : α}, (IsRingHom.{u1, u2} α β _inst_1 _inst_2 f) -> (Eq.{succ u2} β (f (HSub.hSub.{u1, u1, u1} α α α (instHSub.{u1} α (SubNegMonoid.toHasSub.{u1} α (AddGroup.toSubNegMonoid.{u1} α (AddGroupWithOne.toAddGroup.{u1} α (AddCommGroupWithOne.toAddGroupWithOne.{u1} α (Ring.toAddCommGroupWithOne.{u1} α _inst_1)))))) x y)) (HSub.hSub.{u2, u2, u2} β β β (instHSub.{u2} β (SubNegMonoid.toHasSub.{u2} β (AddGroup.toSubNegMonoid.{u2} β (AddGroupWithOne.toAddGroup.{u2} β (AddCommGroupWithOne.toAddGroupWithOne.{u2} β (Ring.toAddCommGroupWithOne.{u2} β _inst_2)))))) (f x) (f y)))
-but is expected to have type
-  forall {α : Type.{u1}} {β : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} β] {f : α -> β} {x : α} {y : α}, (IsRingHom.{u1, u2} α β _inst_1 _inst_2 f) -> (Eq.{succ u2} β (f (HSub.hSub.{u1, u1, u1} α α α (instHSub.{u1} α (Ring.toSub.{u1} α _inst_1)) x y)) (HSub.hSub.{u2, u2, u2} β β β (instHSub.{u2} β (Ring.toSub.{u2} β _inst_2)) (f x) (f y)))
-Case conversion may be inaccurate. Consider using '#align is_ring_hom.map_sub IsRingHom.map_subₓ'. -/
 /-- Ring homomorphisms preserve subtraction. -/
 theorem map_sub (hf : IsRingHom f) : f (x - y) = f x - f y := by
   simp [sub_eq_add_neg, hf.map_add, hf.map_neg]
@@ -166,12 +142,6 @@ theorem id : IsRingHom (@id α) := by refine' { .. } <;> intros <;> rfl
 #align is_ring_hom.id IsRingHom.id
 -/
 
-/- warning: is_ring_hom.comp -> IsRingHom.comp is a dubious translation:
-lean 3 declaration is
-  forall {α : Type.{u1}} {β : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} β] {f : α -> β}, (IsRingHom.{u1, u2} α β _inst_1 _inst_2 f) -> (forall {γ : Type.{u3}} [_inst_3 : Ring.{u3} γ] {g : β -> γ}, (IsRingHom.{u2, u3} β γ _inst_2 _inst_3 g) -> (IsRingHom.{u1, u3} α γ _inst_1 _inst_3 (Function.comp.{succ u1, succ u2, succ u3} α β γ g f)))
-but is expected to have type
-  forall {α : Type.{u2}} {β : Type.{u3}} [_inst_1 : Ring.{u2} α] [_inst_2 : Ring.{u3} β] {f : α -> β}, (IsRingHom.{u2, u3} α β _inst_1 _inst_2 f) -> (forall {γ : Type.{u1}} [_inst_3 : Ring.{u1} γ] {g : β -> γ}, (IsRingHom.{u3, u1} β γ _inst_2 _inst_3 g) -> (IsRingHom.{u2, u1} α γ _inst_1 _inst_3 (Function.comp.{succ u2, succ u3, succ u1} α β γ g f)))
-Case conversion may be inaccurate. Consider using '#align is_ring_hom.comp IsRingHom.compₓ'. -/
 -- see Note [no instance on morphisms]
 /-- The composition of two ring homomorphisms is a ring homomorphism. -/
 theorem comp (hf : IsRingHom f) {γ} [Ring γ] {g : β → γ} (hg : IsRingHom g) : IsRingHom (g ∘ f) :=
@@ -187,12 +157,6 @@ theorem to_isSemiringHom (hf : IsRingHom f) : IsSemiringHom f :=
 #align is_ring_hom.to_is_semiring_hom IsRingHom.to_isSemiringHom
 -/
 
-/- warning: is_ring_hom.to_is_add_group_hom -> IsRingHom.to_isAddGroupHom is a dubious translation:
-lean 3 declaration is
-  forall {α : Type.{u1}} {β : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} β] {f : α -> β}, (IsRingHom.{u1, u2} α β _inst_1 _inst_2 f) -> (IsAddGroupHom.{u1, u2} α β (AddGroupWithOne.toAddGroup.{u1} α (AddCommGroupWithOne.toAddGroupWithOne.{u1} α (Ring.toAddCommGroupWithOne.{u1} α _inst_1))) (AddGroupWithOne.toAddGroup.{u2} β (AddCommGroupWithOne.toAddGroupWithOne.{u2} β (Ring.toAddCommGroupWithOne.{u2} β _inst_2))) f)
-but is expected to have type
-  forall {α : Type.{u1}} {β : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} β] {f : α -> β}, (IsRingHom.{u1, u2} α β _inst_1 _inst_2 f) -> (IsAddGroupHom.{u1, u2} α β (AddGroupWithOne.toAddGroup.{u1} α (Ring.toAddGroupWithOne.{u1} α _inst_1)) (AddGroupWithOne.toAddGroup.{u2} β (Ring.toAddGroupWithOne.{u2} β _inst_2)) f)
-Case conversion may be inaccurate. Consider using '#align is_ring_hom.to_is_add_group_hom IsRingHom.to_isAddGroupHomₓ'. -/
 theorem to_isAddGroupHom (hf : IsRingHom f) : IsAddGroupHom f :=
   { map_add := fun _ _ => hf.map_add }
 #align is_ring_hom.to_is_add_group_hom IsRingHom.to_isAddGroupHom
@@ -214,23 +178,11 @@ def of {f : α → β} (hf : IsSemiringHom f) : α →+* β :=
 #align ring_hom.of RingHom.of
 -/
 
-/- warning: ring_hom.coe_of -> RingHom.coe_of is a dubious translation:
-lean 3 declaration is
-  forall {α : Type.{u1}} {β : Type.{u2}} [rα : Semiring.{u1} α] [rβ : Semiring.{u2} β] {f : α -> β} (hf : IsSemiringHom.{u1, u2} α β rα rβ f), Eq.{max (succ u1) (succ u2)} (α -> β) (coeFn.{max (succ u1) (succ u2), max (succ u1) (succ u2)} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) (fun (_x : RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) => α -> β) (RingHom.hasCoeToFun.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) (RingHom.of.{u1, u2} α β rα rβ f hf)) f
-but is expected to have type
-  forall {α : Type.{u1}} {β : Type.{u2}} {rα : Semiring.{u1} α} {rβ : Semiring.{u2} β} {f : α -> β} (hf : IsSemiringHom.{u1, u2} α β rα rβ f), Eq.{max (succ u1) (succ u2)} (forall (ᾰ : α), (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2397 : α) => β) ᾰ) (FunLike.coe.{max (succ u1) (succ u2), succ u1, succ u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α (fun (_x : α) => (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2397 : α) => β) _x) (MulHomClass.toFunLike.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonUnitalNonAssocSemiring.toMul.{u1} α (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα))) (NonUnitalNonAssocSemiring.toMul.{u2} β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ))) (NonUnitalRingHomClass.toMulHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα)) (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ)) (RingHomClass.toNonUnitalRingHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ) (RingHom.instRingHomClassRingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ))))) (RingHom.of.{u1, u2} α β rα rβ f hf)) f
-Case conversion may be inaccurate. Consider using '#align ring_hom.coe_of RingHom.coe_ofₓ'. -/
 @[simp]
 theorem coe_of {f : α → β} (hf : IsSemiringHom f) : ⇑(of hf) = f :=
   rfl
 #align ring_hom.coe_of RingHom.coe_of
 
-/- warning: ring_hom.to_is_semiring_hom -> RingHom.to_isSemiringHom is a dubious translation:
-lean 3 declaration is
-  forall {α : Type.{u1}} {β : Type.{u2}} [rα : Semiring.{u1} α] [rβ : Semiring.{u2} β] (f : RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)), IsSemiringHom.{u1, u2} α β rα rβ (coeFn.{max (succ u1) (succ u2), max (succ u1) (succ u2)} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) (fun (_x : RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) => α -> β) (RingHom.hasCoeToFun.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) f)
-but is expected to have type
-  forall {α : Type.{u1}} {β : Type.{u2}} {rα : Semiring.{u1} α} {rβ : Semiring.{u2} β} (f : RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)), IsSemiringHom.{u1, u2} α β rα rβ (FunLike.coe.{max (succ u1) (succ u2), succ u1, succ u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α (fun (_x : α) => (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2397 : α) => β) _x) (MulHomClass.toFunLike.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonUnitalNonAssocSemiring.toMul.{u1} α (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα))) (NonUnitalNonAssocSemiring.toMul.{u2} β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ))) (NonUnitalRingHomClass.toMulHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα)) (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ)) (RingHomClass.toNonUnitalRingHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ) (RingHom.instRingHomClassRingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ))))) f)
-Case conversion may be inaccurate. Consider using '#align ring_hom.to_is_semiring_hom RingHom.to_isSemiringHomₓ'. -/
 theorem to_isSemiringHom (f : α →+* β) : IsSemiringHom f :=
   { map_zero := f.map_zero
     map_one := f.map_one
@@ -240,12 +192,6 @@ theorem to_isSemiringHom (f : α →+* β) : IsSemiringHom f :=
 
 end
 
-/- warning: ring_hom.to_is_ring_hom -> RingHom.to_isRingHom is a dubious translation:
-lean 3 declaration is
-  forall {α : Type.{u1}} {γ : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} γ] (g : RingHom.{u1, u2} α γ (NonAssocRing.toNonAssocSemiring.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u2} γ (Ring.toNonAssocRing.{u2} γ _inst_2))), IsRingHom.{u1, u2} α γ _inst_1 _inst_2 (coeFn.{max (succ u1) (succ u2), max (succ u1) (succ u2)} (RingHom.{u1, u2} α γ (NonAssocRing.toNonAssocSemiring.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u2} γ (Ring.toNonAssocRing.{u2} γ _inst_2))) (fun (_x : RingHom.{u1, u2} α γ (NonAssocRing.toNonAssocSemiring.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u2} γ (Ring.toNonAssocRing.{u2} γ _inst_2))) => α -> γ) (RingHom.hasCoeToFun.{u1, u2} α γ (NonAssocRing.toNonAssocSemiring.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u2} γ (Ring.toNonAssocRing.{u2} γ _inst_2))) g)
-but is expected to have type
-  forall {α : Type.{u2}} {γ : Type.{u1}} [_inst_1 : Ring.{u2} α] [_inst_2 : Ring.{u1} γ] (g : RingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))), IsRingHom.{u2, u1} α γ _inst_1 _inst_2 (FunLike.coe.{max (succ u2) (succ u1), succ u2, succ u1} (RingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))) α (fun (_x : α) => (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2397 : α) => γ) _x) (MulHomClass.toFunLike.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))) α γ (NonUnitalNonAssocSemiring.toMul.{u2} α (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} α (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)))) (NonUnitalNonAssocSemiring.toMul.{u1} γ (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} γ (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2)))) (NonUnitalRingHomClass.toMulHomClass.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))) α γ (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} α (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1))) (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} γ (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))) (RingHomClass.toNonUnitalRingHomClass.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))) α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2)) (RingHom.instRingHomClassRingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2)))))) g)
-Case conversion may be inaccurate. Consider using '#align ring_hom.to_is_ring_hom RingHom.to_isRingHomₓ'. -/
 theorem to_isRingHom {α γ} [Ring α] [Ring γ] (g : α →+* γ) : IsRingHom g :=
   IsRingHom.of_semiring g.to_isSemiringHom
 #align ring_hom.to_is_ring_hom RingHom.to_isRingHom

mathlib commit https://github.com/leanprover-community/mathlib/commit/95a87616d63b3cb49d3fe678d416fbe9c4217bf4

@@ -218,7 +218,7 @@ def of {f : α → β} (hf : IsSemiringHom f) : α →+* β :=
 lean 3 declaration is
   forall {α : Type.{u1}} {β : Type.{u2}} [rα : Semiring.{u1} α] [rβ : Semiring.{u2} β] {f : α -> β} (hf : IsSemiringHom.{u1, u2} α β rα rβ f), Eq.{max (succ u1) (succ u2)} (α -> β) (coeFn.{max (succ u1) (succ u2), max (succ u1) (succ u2)} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) (fun (_x : RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) => α -> β) (RingHom.hasCoeToFun.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) (RingHom.of.{u1, u2} α β rα rβ f hf)) f
 but is expected to have type
-  forall {α : Type.{u1}} {β : Type.{u2}} {rα : Semiring.{u1} α} {rβ : Semiring.{u2} β} {f : α -> β} (hf : IsSemiringHom.{u1, u2} α β rα rβ f), Eq.{max (succ u1) (succ u2)} (forall (ᾰ : α), (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2391 : α) => β) ᾰ) (FunLike.coe.{max (succ u1) (succ u2), succ u1, succ u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α (fun (_x : α) => (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2391 : α) => β) _x) (MulHomClass.toFunLike.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonUnitalNonAssocSemiring.toMul.{u1} α (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα))) (NonUnitalNonAssocSemiring.toMul.{u2} β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ))) (NonUnitalRingHomClass.toMulHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα)) (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ)) (RingHomClass.toNonUnitalRingHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ) (RingHom.instRingHomClassRingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ))))) (RingHom.of.{u1, u2} α β rα rβ f hf)) f
+  forall {α : Type.{u1}} {β : Type.{u2}} {rα : Semiring.{u1} α} {rβ : Semiring.{u2} β} {f : α -> β} (hf : IsSemiringHom.{u1, u2} α β rα rβ f), Eq.{max (succ u1) (succ u2)} (forall (ᾰ : α), (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2397 : α) => β) ᾰ) (FunLike.coe.{max (succ u1) (succ u2), succ u1, succ u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α (fun (_x : α) => (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2397 : α) => β) _x) (MulHomClass.toFunLike.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonUnitalNonAssocSemiring.toMul.{u1} α (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα))) (NonUnitalNonAssocSemiring.toMul.{u2} β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ))) (NonUnitalRingHomClass.toMulHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα)) (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ)) (RingHomClass.toNonUnitalRingHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ) (RingHom.instRingHomClassRingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ))))) (RingHom.of.{u1, u2} α β rα rβ f hf)) f
 Case conversion may be inaccurate. Consider using '#align ring_hom.coe_of RingHom.coe_ofₓ'. -/
 @[simp]
 theorem coe_of {f : α → β} (hf : IsSemiringHom f) : ⇑(of hf) = f :=
@@ -229,7 +229,7 @@ theorem coe_of {f : α → β} (hf : IsSemiringHom f) : ⇑(of hf) = f :=
 lean 3 declaration is
   forall {α : Type.{u1}} {β : Type.{u2}} [rα : Semiring.{u1} α] [rβ : Semiring.{u2} β] (f : RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)), IsSemiringHom.{u1, u2} α β rα rβ (coeFn.{max (succ u1) (succ u2), max (succ u1) (succ u2)} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) (fun (_x : RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) => α -> β) (RingHom.hasCoeToFun.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) f)
 but is expected to have type
-  forall {α : Type.{u1}} {β : Type.{u2}} {rα : Semiring.{u1} α} {rβ : Semiring.{u2} β} (f : RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)), IsSemiringHom.{u1, u2} α β rα rβ (FunLike.coe.{max (succ u1) (succ u2), succ u1, succ u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α (fun (_x : α) => (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2391 : α) => β) _x) (MulHomClass.toFunLike.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonUnitalNonAssocSemiring.toMul.{u1} α (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα))) (NonUnitalNonAssocSemiring.toMul.{u2} β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ))) (NonUnitalRingHomClass.toMulHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα)) (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ)) (RingHomClass.toNonUnitalRingHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ) (RingHom.instRingHomClassRingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ))))) f)
+  forall {α : Type.{u1}} {β : Type.{u2}} {rα : Semiring.{u1} α} {rβ : Semiring.{u2} β} (f : RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)), IsSemiringHom.{u1, u2} α β rα rβ (FunLike.coe.{max (succ u1) (succ u2), succ u1, succ u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α (fun (_x : α) => (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2397 : α) => β) _x) (MulHomClass.toFunLike.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonUnitalNonAssocSemiring.toMul.{u1} α (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα))) (NonUnitalNonAssocSemiring.toMul.{u2} β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ))) (NonUnitalRingHomClass.toMulHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα)) (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ)) (RingHomClass.toNonUnitalRingHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ) (RingHom.instRingHomClassRingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ))))) f)
 Case conversion may be inaccurate. Consider using '#align ring_hom.to_is_semiring_hom RingHom.to_isSemiringHomₓ'. -/
 theorem to_isSemiringHom (f : α →+* β) : IsSemiringHom f :=
   { map_zero := f.map_zero
@@ -244,7 +244,7 @@ end
 lean 3 declaration is
   forall {α : Type.{u1}} {γ : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} γ] (g : RingHom.{u1, u2} α γ (NonAssocRing.toNonAssocSemiring.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u2} γ (Ring.toNonAssocRing.{u2} γ _inst_2))), IsRingHom.{u1, u2} α γ _inst_1 _inst_2 (coeFn.{max (succ u1) (succ u2), max (succ u1) (succ u2)} (RingHom.{u1, u2} α γ (NonAssocRing.toNonAssocSemiring.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u2} γ (Ring.toNonAssocRing.{u2} γ _inst_2))) (fun (_x : RingHom.{u1, u2} α γ (NonAssocRing.toNonAssocSemiring.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u2} γ (Ring.toNonAssocRing.{u2} γ _inst_2))) => α -> γ) (RingHom.hasCoeToFun.{u1, u2} α γ (NonAssocRing.toNonAssocSemiring.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u2} γ (Ring.toNonAssocRing.{u2} γ _inst_2))) g)
 but is expected to have type
-  forall {α : Type.{u2}} {γ : Type.{u1}} [_inst_1 : Ring.{u2} α] [_inst_2 : Ring.{u1} γ] (g : RingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))), IsRingHom.{u2, u1} α γ _inst_1 _inst_2 (FunLike.coe.{max (succ u2) (succ u1), succ u2, succ u1} (RingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))) α (fun (_x : α) => (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2391 : α) => γ) _x) (MulHomClass.toFunLike.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))) α γ (NonUnitalNonAssocSemiring.toMul.{u2} α (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} α (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)))) (NonUnitalNonAssocSemiring.toMul.{u1} γ (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} γ (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2)))) (NonUnitalRingHomClass.toMulHomClass.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))) α γ (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} α (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1))) (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} γ (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))) (RingHomClass.toNonUnitalRingHomClass.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))) α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2)) (RingHom.instRingHomClassRingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2)))))) g)
+  forall {α : Type.{u2}} {γ : Type.{u1}} [_inst_1 : Ring.{u2} α] [_inst_2 : Ring.{u1} γ] (g : RingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))), IsRingHom.{u2, u1} α γ _inst_1 _inst_2 (FunLike.coe.{max (succ u2) (succ u1), succ u2, succ u1} (RingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))) α (fun (_x : α) => (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2397 : α) => γ) _x) (MulHomClass.toFunLike.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))) α γ (NonUnitalNonAssocSemiring.toMul.{u2} α (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} α (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)))) (NonUnitalNonAssocSemiring.toMul.{u1} γ (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} γ (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2)))) (NonUnitalRingHomClass.toMulHomClass.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))) α γ (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} α (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1))) (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} γ (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))) (RingHomClass.toNonUnitalRingHomClass.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))) α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2)) (RingHom.instRingHomClassRingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2)))))) g)
 Case conversion may be inaccurate. Consider using '#align ring_hom.to_is_ring_hom RingHom.to_isRingHomₓ'. -/
 theorem to_isRingHom {α γ} [Ring α] [Ring γ] (g : α →+* γ) : IsRingHom g :=
   IsRingHom.of_semiring g.to_isSemiringHom

mathlib commit https://github.com/leanprover-community/mathlib/commit/08e1d8d4d989df3a6df86f385e9053ec8a372cc1

@@ -244,7 +244,7 @@ end
 lean 3 declaration is
   forall {α : Type.{u1}} {γ : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} γ] (g : RingHom.{u1, u2} α γ (NonAssocRing.toNonAssocSemiring.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u2} γ (Ring.toNonAssocRing.{u2} γ _inst_2))), IsRingHom.{u1, u2} α γ _inst_1 _inst_2 (coeFn.{max (succ u1) (succ u2), max (succ u1) (succ u2)} (RingHom.{u1, u2} α γ (NonAssocRing.toNonAssocSemiring.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u2} γ (Ring.toNonAssocRing.{u2} γ _inst_2))) (fun (_x : RingHom.{u1, u2} α γ (NonAssocRing.toNonAssocSemiring.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u2} γ (Ring.toNonAssocRing.{u2} γ _inst_2))) => α -> γ) (RingHom.hasCoeToFun.{u1, u2} α γ (NonAssocRing.toNonAssocSemiring.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u2} γ (Ring.toNonAssocRing.{u2} γ _inst_2))) g)
 but is expected to have type
-  forall {α : Type.{u2}} {γ : Type.{u1}} [_inst_1 : Ring.{u2} α] [_inst_2 : Ring.{u1} γ] (g : RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))), IsRingHom.{u2, u1} α γ _inst_1 _inst_2 (FunLike.coe.{max (succ u2) (succ u1), succ u2, succ u1} (RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) α (fun (_x : α) => (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2391 : α) => γ) _x) (MulHomClass.toFunLike.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) α γ (NonUnitalNonAssocSemiring.toMul.{u2} α (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} α (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)))) (NonUnitalNonAssocSemiring.toMul.{u1} γ (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} γ (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2)))) (NonUnitalRingHomClass.toMulHomClass.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) α γ (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} α (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1))) (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} γ (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) (RingHomClass.toNonUnitalRingHomClass.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2)) (RingHom.instRingHomClassRingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2)))))) g)
+  forall {α : Type.{u2}} {γ : Type.{u1}} [_inst_1 : Ring.{u2} α] [_inst_2 : Ring.{u1} γ] (g : RingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))), IsRingHom.{u2, u1} α γ _inst_1 _inst_2 (FunLike.coe.{max (succ u2) (succ u1), succ u2, succ u1} (RingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))) α (fun (_x : α) => (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2391 : α) => γ) _x) (MulHomClass.toFunLike.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))) α γ (NonUnitalNonAssocSemiring.toMul.{u2} α (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} α (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)))) (NonUnitalNonAssocSemiring.toMul.{u1} γ (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} γ (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2)))) (NonUnitalRingHomClass.toMulHomClass.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))) α γ (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} α (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1))) (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} γ (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))) (RingHomClass.toNonUnitalRingHomClass.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2))) α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2)) (RingHom.instRingHomClassRingHom.{u2, u1} α γ (Semiring.toNonAssocSemiring.{u2} α (Ring.toSemiring.{u2} α _inst_1)) (Semiring.toNonAssocSemiring.{u1} γ (Ring.toSemiring.{u1} γ _inst_2)))))) g)
 Case conversion may be inaccurate. Consider using '#align ring_hom.to_is_ring_hom RingHom.to_isRingHomₓ'. -/
 theorem to_isRingHom {α γ} [Ring α] [Ring γ] (g : α →+* γ) : IsRingHom g :=
   IsRingHom.of_semiring g.to_isSemiringHom

mathlib commit https://github.com/leanprover-community/mathlib/commit/09079525fd01b3dda35e96adaa08d2f943e1648c

@@ -40,10 +40,10 @@ universe u v w
 variable {α : Type u}
 
 #print IsSemiringHom /-
-/- ./././Mathport/Syntax/Translate/Command.lean:388:30: infer kinds are unsupported in Lean 4: #[`map_zero] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:388:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:388:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:388:30: infer kinds are unsupported in Lean 4: #[`map_mul] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_zero] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_mul] [] -/
 /-- Predicate for semiring homomorphisms (deprecated -- use the bundled `ring_hom` version). -/
 structure IsSemiringHom {α : Type u} {β : Type v} [Semiring α] [Semiring β] (f : α → β) : Prop where
   map_zero : f 0 = 0
@@ -97,9 +97,9 @@ theorem to_isMonoidHom (hf : IsSemiringHom f) : IsMonoidHom f :=
 end IsSemiringHom
 
 #print IsRingHom /-
-/- ./././Mathport/Syntax/Translate/Command.lean:388:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:388:30: infer kinds are unsupported in Lean 4: #[`map_mul] [] -/
-/- ./././Mathport/Syntax/Translate/Command.lean:388:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_one] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_mul] [] -/
+/- ./././Mathport/Syntax/Translate/Command.lean:393:30: infer kinds are unsupported in Lean 4: #[`map_add] [] -/
 /-- Predicate for ring homomorphisms (deprecated -- use the bundled `ring_hom` version). -/
 structure IsRingHom {α : Type u} {β : Type v} [Ring α] [Ring β] (f : α → β) : Prop where
   map_one : f 1 = 1

mathlib commit https://github.com/leanprover-community/mathlib/commit/ce86f4e05e9a9b8da5e316b22c76ce76440c56a1

@@ -137,7 +137,7 @@ theorem map_zero (hf : IsRingHom f) : f 0 = 0 :=
 
 /- warning: is_ring_hom.map_neg -> IsRingHom.map_neg is a dubious translation:
 lean 3 declaration is
-  forall {α : Type.{u1}} {β : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} β] {f : α -> β} {x : α}, (IsRingHom.{u1, u2} α β _inst_1 _inst_2 f) -> (Eq.{succ u2} β (f (Neg.neg.{u1} α (SubNegMonoid.toHasNeg.{u1} α (AddGroup.toSubNegMonoid.{u1} α (AddGroupWithOne.toAddGroup.{u1} α (NonAssocRing.toAddGroupWithOne.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1))))) x)) (Neg.neg.{u2} β (SubNegMonoid.toHasNeg.{u2} β (AddGroup.toSubNegMonoid.{u2} β (AddGroupWithOne.toAddGroup.{u2} β (NonAssocRing.toAddGroupWithOne.{u2} β (Ring.toNonAssocRing.{u2} β _inst_2))))) (f x)))
+  forall {α : Type.{u1}} {β : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} β] {f : α -> β} {x : α}, (IsRingHom.{u1, u2} α β _inst_1 _inst_2 f) -> (Eq.{succ u2} β (f (Neg.neg.{u1} α (SubNegMonoid.toHasNeg.{u1} α (AddGroup.toSubNegMonoid.{u1} α (AddGroupWithOne.toAddGroup.{u1} α (AddCommGroupWithOne.toAddGroupWithOne.{u1} α (Ring.toAddCommGroupWithOne.{u1} α _inst_1))))) x)) (Neg.neg.{u2} β (SubNegMonoid.toHasNeg.{u2} β (AddGroup.toSubNegMonoid.{u2} β (AddGroupWithOne.toAddGroup.{u2} β (AddCommGroupWithOne.toAddGroupWithOne.{u2} β (Ring.toAddCommGroupWithOne.{u2} β _inst_2))))) (f x)))
 but is expected to have type
   forall {α : Type.{u1}} {β : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} β] {f : α -> β} {x : α}, (IsRingHom.{u1, u2} α β _inst_1 _inst_2 f) -> (Eq.{succ u2} β (f (Neg.neg.{u1} α (Ring.toNeg.{u1} α _inst_1) x)) (Neg.neg.{u2} β (Ring.toNeg.{u2} β _inst_2) (f x)))
 Case conversion may be inaccurate. Consider using '#align is_ring_hom.map_neg IsRingHom.map_negₓ'. -/
@@ -151,7 +151,7 @@ theorem map_neg (hf : IsRingHom f) : f (-x) = -f x :=
 
 /- warning: is_ring_hom.map_sub -> IsRingHom.map_sub is a dubious translation:
 lean 3 declaration is
-  forall {α : Type.{u1}} {β : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} β] {f : α -> β} {x : α} {y : α}, (IsRingHom.{u1, u2} α β _inst_1 _inst_2 f) -> (Eq.{succ u2} β (f (HSub.hSub.{u1, u1, u1} α α α (instHSub.{u1} α (SubNegMonoid.toHasSub.{u1} α (AddGroup.toSubNegMonoid.{u1} α (AddGroupWithOne.toAddGroup.{u1} α (NonAssocRing.toAddGroupWithOne.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1)))))) x y)) (HSub.hSub.{u2, u2, u2} β β β (instHSub.{u2} β (SubNegMonoid.toHasSub.{u2} β (AddGroup.toSubNegMonoid.{u2} β (AddGroupWithOne.toAddGroup.{u2} β (NonAssocRing.toAddGroupWithOne.{u2} β (Ring.toNonAssocRing.{u2} β _inst_2)))))) (f x) (f y)))
+  forall {α : Type.{u1}} {β : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} β] {f : α -> β} {x : α} {y : α}, (IsRingHom.{u1, u2} α β _inst_1 _inst_2 f) -> (Eq.{succ u2} β (f (HSub.hSub.{u1, u1, u1} α α α (instHSub.{u1} α (SubNegMonoid.toHasSub.{u1} α (AddGroup.toSubNegMonoid.{u1} α (AddGroupWithOne.toAddGroup.{u1} α (AddCommGroupWithOne.toAddGroupWithOne.{u1} α (Ring.toAddCommGroupWithOne.{u1} α _inst_1)))))) x y)) (HSub.hSub.{u2, u2, u2} β β β (instHSub.{u2} β (SubNegMonoid.toHasSub.{u2} β (AddGroup.toSubNegMonoid.{u2} β (AddGroupWithOne.toAddGroup.{u2} β (AddCommGroupWithOne.toAddGroupWithOne.{u2} β (Ring.toAddCommGroupWithOne.{u2} β _inst_2)))))) (f x) (f y)))
 but is expected to have type
   forall {α : Type.{u1}} {β : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} β] {f : α -> β} {x : α} {y : α}, (IsRingHom.{u1, u2} α β _inst_1 _inst_2 f) -> (Eq.{succ u2} β (f (HSub.hSub.{u1, u1, u1} α α α (instHSub.{u1} α (Ring.toSub.{u1} α _inst_1)) x y)) (HSub.hSub.{u2, u2, u2} β β β (instHSub.{u2} β (Ring.toSub.{u2} β _inst_2)) (f x) (f y)))
 Case conversion may be inaccurate. Consider using '#align is_ring_hom.map_sub IsRingHom.map_subₓ'. -/
@@ -189,7 +189,7 @@ theorem to_isSemiringHom (hf : IsRingHom f) : IsSemiringHom f :=
 
 /- warning: is_ring_hom.to_is_add_group_hom -> IsRingHom.to_isAddGroupHom is a dubious translation:
 lean 3 declaration is
-  forall {α : Type.{u1}} {β : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} β] {f : α -> β}, (IsRingHom.{u1, u2} α β _inst_1 _inst_2 f) -> (IsAddGroupHom.{u1, u2} α β (AddGroupWithOne.toAddGroup.{u1} α (NonAssocRing.toAddGroupWithOne.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1))) (AddGroupWithOne.toAddGroup.{u2} β (NonAssocRing.toAddGroupWithOne.{u2} β (Ring.toNonAssocRing.{u2} β _inst_2))) f)
+  forall {α : Type.{u1}} {β : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} β] {f : α -> β}, (IsRingHom.{u1, u2} α β _inst_1 _inst_2 f) -> (IsAddGroupHom.{u1, u2} α β (AddGroupWithOne.toAddGroup.{u1} α (AddCommGroupWithOne.toAddGroupWithOne.{u1} α (Ring.toAddCommGroupWithOne.{u1} α _inst_1))) (AddGroupWithOne.toAddGroup.{u2} β (AddCommGroupWithOne.toAddGroupWithOne.{u2} β (Ring.toAddCommGroupWithOne.{u2} β _inst_2))) f)
 but is expected to have type
   forall {α : Type.{u1}} {β : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} β] {f : α -> β}, (IsRingHom.{u1, u2} α β _inst_1 _inst_2 f) -> (IsAddGroupHom.{u1, u2} α β (AddGroupWithOne.toAddGroup.{u1} α (Ring.toAddGroupWithOne.{u1} α _inst_1)) (AddGroupWithOne.toAddGroup.{u2} β (Ring.toAddGroupWithOne.{u2} β _inst_2)) f)
 Case conversion may be inaccurate. Consider using '#align is_ring_hom.to_is_add_group_hom IsRingHom.to_isAddGroupHomₓ'. -/

mathlib commit https://github.com/leanprover-community/mathlib/commit/b19481deb571022990f1baa9cbf9172e6757a479

@@ -187,11 +187,15 @@ theorem to_isSemiringHom (hf : IsRingHom f) : IsSemiringHom f :=
 #align is_ring_hom.to_is_semiring_hom IsRingHom.to_isSemiringHom
 -/
 
-#print IsRingHom.to_isAddGroupHom /-
+/- warning: is_ring_hom.to_is_add_group_hom -> IsRingHom.to_isAddGroupHom is a dubious translation:
+lean 3 declaration is
+  forall {α : Type.{u1}} {β : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} β] {f : α -> β}, (IsRingHom.{u1, u2} α β _inst_1 _inst_2 f) -> (IsAddGroupHom.{u1, u2} α β (AddGroupWithOne.toAddGroup.{u1} α (NonAssocRing.toAddGroupWithOne.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1))) (AddGroupWithOne.toAddGroup.{u2} β (NonAssocRing.toAddGroupWithOne.{u2} β (Ring.toNonAssocRing.{u2} β _inst_2))) f)
+but is expected to have type
+  forall {α : Type.{u1}} {β : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} β] {f : α -> β}, (IsRingHom.{u1, u2} α β _inst_1 _inst_2 f) -> (IsAddGroupHom.{u1, u2} α β (AddGroupWithOne.toAddGroup.{u1} α (Ring.toAddGroupWithOne.{u1} α _inst_1)) (AddGroupWithOne.toAddGroup.{u2} β (Ring.toAddGroupWithOne.{u2} β _inst_2)) f)
+Case conversion may be inaccurate. Consider using '#align is_ring_hom.to_is_add_group_hom IsRingHom.to_isAddGroupHomₓ'. -/
 theorem to_isAddGroupHom (hf : IsRingHom f) : IsAddGroupHom f :=
   { map_add := fun _ _ => hf.map_add }
 #align is_ring_hom.to_is_add_group_hom IsRingHom.to_isAddGroupHom
--/
 
 end IsRingHom
 

mathlib commit https://github.com/leanprover-community/mathlib/commit/3180fab693e2cee3bff62675571264cb8778b212

@@ -214,7 +214,7 @@ def of {f : α → β} (hf : IsSemiringHom f) : α →+* β :=
 lean 3 declaration is
   forall {α : Type.{u1}} {β : Type.{u2}} [rα : Semiring.{u1} α] [rβ : Semiring.{u2} β] {f : α -> β} (hf : IsSemiringHom.{u1, u2} α β rα rβ f), Eq.{max (succ u1) (succ u2)} (α -> β) (coeFn.{max (succ u1) (succ u2), max (succ u1) (succ u2)} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) (fun (_x : RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) => α -> β) (RingHom.hasCoeToFun.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) (RingHom.of.{u1, u2} α β rα rβ f hf)) f
 but is expected to have type
-  forall {α : Type.{u1}} {β : Type.{u2}} {rα : Semiring.{u1} α} {rβ : Semiring.{u2} β} {f : α -> β} (hf : IsSemiringHom.{u1, u2} α β rα rβ f), Eq.{max (succ u1) (succ u2)} (forall (ᾰ : α), (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2372 : α) => β) ᾰ) (FunLike.coe.{max (succ u1) (succ u2), succ u1, succ u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α (fun (_x : α) => (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2372 : α) => β) _x) (MulHomClass.toFunLike.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonUnitalNonAssocSemiring.toMul.{u1} α (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα))) (NonUnitalNonAssocSemiring.toMul.{u2} β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ))) (NonUnitalRingHomClass.toMulHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα)) (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ)) (RingHomClass.toNonUnitalRingHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ) (RingHom.instRingHomClassRingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ))))) (RingHom.of.{u1, u2} α β rα rβ f hf)) f
+  forall {α : Type.{u1}} {β : Type.{u2}} {rα : Semiring.{u1} α} {rβ : Semiring.{u2} β} {f : α -> β} (hf : IsSemiringHom.{u1, u2} α β rα rβ f), Eq.{max (succ u1) (succ u2)} (forall (ᾰ : α), (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2391 : α) => β) ᾰ) (FunLike.coe.{max (succ u1) (succ u2), succ u1, succ u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α (fun (_x : α) => (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2391 : α) => β) _x) (MulHomClass.toFunLike.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonUnitalNonAssocSemiring.toMul.{u1} α (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα))) (NonUnitalNonAssocSemiring.toMul.{u2} β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ))) (NonUnitalRingHomClass.toMulHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα)) (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ)) (RingHomClass.toNonUnitalRingHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ) (RingHom.instRingHomClassRingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ))))) (RingHom.of.{u1, u2} α β rα rβ f hf)) f
 Case conversion may be inaccurate. Consider using '#align ring_hom.coe_of RingHom.coe_ofₓ'. -/
 @[simp]
 theorem coe_of {f : α → β} (hf : IsSemiringHom f) : ⇑(of hf) = f :=
@@ -225,7 +225,7 @@ theorem coe_of {f : α → β} (hf : IsSemiringHom f) : ⇑(of hf) = f :=
 lean 3 declaration is
   forall {α : Type.{u1}} {β : Type.{u2}} [rα : Semiring.{u1} α] [rβ : Semiring.{u2} β] (f : RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)), IsSemiringHom.{u1, u2} α β rα rβ (coeFn.{max (succ u1) (succ u2), max (succ u1) (succ u2)} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) (fun (_x : RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) => α -> β) (RingHom.hasCoeToFun.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) f)
 but is expected to have type
-  forall {α : Type.{u1}} {β : Type.{u2}} {rα : Semiring.{u1} α} {rβ : Semiring.{u2} β} (f : RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)), IsSemiringHom.{u1, u2} α β rα rβ (FunLike.coe.{max (succ u1) (succ u2), succ u1, succ u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α (fun (_x : α) => (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2372 : α) => β) _x) (MulHomClass.toFunLike.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonUnitalNonAssocSemiring.toMul.{u1} α (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα))) (NonUnitalNonAssocSemiring.toMul.{u2} β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ))) (NonUnitalRingHomClass.toMulHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα)) (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ)) (RingHomClass.toNonUnitalRingHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ) (RingHom.instRingHomClassRingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ))))) f)
+  forall {α : Type.{u1}} {β : Type.{u2}} {rα : Semiring.{u1} α} {rβ : Semiring.{u2} β} (f : RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)), IsSemiringHom.{u1, u2} α β rα rβ (FunLike.coe.{max (succ u1) (succ u2), succ u1, succ u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α (fun (_x : α) => (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2391 : α) => β) _x) (MulHomClass.toFunLike.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonUnitalNonAssocSemiring.toMul.{u1} α (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα))) (NonUnitalNonAssocSemiring.toMul.{u2} β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ))) (NonUnitalRingHomClass.toMulHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα)) (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ)) (RingHomClass.toNonUnitalRingHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ) (RingHom.instRingHomClassRingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ))))) f)
 Case conversion may be inaccurate. Consider using '#align ring_hom.to_is_semiring_hom RingHom.to_isSemiringHomₓ'. -/
 theorem to_isSemiringHom (f : α →+* β) : IsSemiringHom f :=
   { map_zero := f.map_zero
@@ -240,7 +240,7 @@ end
 lean 3 declaration is
   forall {α : Type.{u1}} {γ : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} γ] (g : RingHom.{u1, u2} α γ (NonAssocRing.toNonAssocSemiring.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u2} γ (Ring.toNonAssocRing.{u2} γ _inst_2))), IsRingHom.{u1, u2} α γ _inst_1 _inst_2 (coeFn.{max (succ u1) (succ u2), max (succ u1) (succ u2)} (RingHom.{u1, u2} α γ (NonAssocRing.toNonAssocSemiring.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u2} γ (Ring.toNonAssocRing.{u2} γ _inst_2))) (fun (_x : RingHom.{u1, u2} α γ (NonAssocRing.toNonAssocSemiring.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u2} γ (Ring.toNonAssocRing.{u2} γ _inst_2))) => α -> γ) (RingHom.hasCoeToFun.{u1, u2} α γ (NonAssocRing.toNonAssocSemiring.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u2} γ (Ring.toNonAssocRing.{u2} γ _inst_2))) g)
 but is expected to have type
-  forall {α : Type.{u2}} {γ : Type.{u1}} [_inst_1 : Ring.{u2} α] [_inst_2 : Ring.{u1} γ] (g : RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))), IsRingHom.{u2, u1} α γ _inst_1 _inst_2 (FunLike.coe.{max (succ u2) (succ u1), succ u2, succ u1} (RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) α (fun (_x : α) => (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2372 : α) => γ) _x) (MulHomClass.toFunLike.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) α γ (NonUnitalNonAssocSemiring.toMul.{u2} α (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} α (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)))) (NonUnitalNonAssocSemiring.toMul.{u1} γ (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} γ (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2)))) (NonUnitalRingHomClass.toMulHomClass.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) α γ (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} α (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1))) (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} γ (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) (RingHomClass.toNonUnitalRingHomClass.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2)) (RingHom.instRingHomClassRingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2)))))) g)
+  forall {α : Type.{u2}} {γ : Type.{u1}} [_inst_1 : Ring.{u2} α] [_inst_2 : Ring.{u1} γ] (g : RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))), IsRingHom.{u2, u1} α γ _inst_1 _inst_2 (FunLike.coe.{max (succ u2) (succ u1), succ u2, succ u1} (RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) α (fun (_x : α) => (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2391 : α) => γ) _x) (MulHomClass.toFunLike.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) α γ (NonUnitalNonAssocSemiring.toMul.{u2} α (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} α (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)))) (NonUnitalNonAssocSemiring.toMul.{u1} γ (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} γ (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2)))) (NonUnitalRingHomClass.toMulHomClass.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) α γ (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} α (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1))) (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} γ (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) (RingHomClass.toNonUnitalRingHomClass.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2)) (RingHom.instRingHomClassRingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2)))))) g)
 Case conversion may be inaccurate. Consider using '#align ring_hom.to_is_ring_hom RingHom.to_isRingHomₓ'. -/
 theorem to_isRingHom {α γ} [Ring α] [Ring γ] (g : α →+* γ) : IsRingHom g :=
   IsRingHom.of_semiring g.to_isSemiringHom

mathlib commit https://github.com/leanprover-community/mathlib/commit/38f16f960f5006c6c0c2bac7b0aba5273188f4e5

@@ -214,7 +214,7 @@ def of {f : α → β} (hf : IsSemiringHom f) : α →+* β :=
 lean 3 declaration is
   forall {α : Type.{u1}} {β : Type.{u2}} [rα : Semiring.{u1} α] [rβ : Semiring.{u2} β] {f : α -> β} (hf : IsSemiringHom.{u1, u2} α β rα rβ f), Eq.{max (succ u1) (succ u2)} (α -> β) (coeFn.{max (succ u1) (succ u2), max (succ u1) (succ u2)} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) (fun (_x : RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) => α -> β) (RingHom.hasCoeToFun.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) (RingHom.of.{u1, u2} α β rα rβ f hf)) f
 but is expected to have type
-  forall {α : Type.{u1}} {β : Type.{u2}} {rα : Semiring.{u1} α} {rβ : Semiring.{u2} β} {f : α -> β} (hf : IsSemiringHom.{u1, u2} α β rα rβ f), Eq.{max (succ u1) (succ u2)} (forall (ᾰ : α), (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2398 : α) => β) ᾰ) (FunLike.coe.{max (succ u1) (succ u2), succ u1, succ u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α (fun (_x : α) => (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2398 : α) => β) _x) (MulHomClass.toFunLike.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonUnitalNonAssocSemiring.toMul.{u1} α (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα))) (NonUnitalNonAssocSemiring.toMul.{u2} β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ))) (NonUnitalRingHomClass.toMulHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα)) (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ)) (RingHomClass.toNonUnitalRingHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ) (RingHom.instRingHomClassRingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ))))) (RingHom.of.{u1, u2} α β rα rβ f hf)) f
+  forall {α : Type.{u1}} {β : Type.{u2}} {rα : Semiring.{u1} α} {rβ : Semiring.{u2} β} {f : α -> β} (hf : IsSemiringHom.{u1, u2} α β rα rβ f), Eq.{max (succ u1) (succ u2)} (forall (ᾰ : α), (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2372 : α) => β) ᾰ) (FunLike.coe.{max (succ u1) (succ u2), succ u1, succ u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α (fun (_x : α) => (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2372 : α) => β) _x) (MulHomClass.toFunLike.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonUnitalNonAssocSemiring.toMul.{u1} α (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα))) (NonUnitalNonAssocSemiring.toMul.{u2} β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ))) (NonUnitalRingHomClass.toMulHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα)) (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ)) (RingHomClass.toNonUnitalRingHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ) (RingHom.instRingHomClassRingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ))))) (RingHom.of.{u1, u2} α β rα rβ f hf)) f
 Case conversion may be inaccurate. Consider using '#align ring_hom.coe_of RingHom.coe_ofₓ'. -/
 @[simp]
 theorem coe_of {f : α → β} (hf : IsSemiringHom f) : ⇑(of hf) = f :=
@@ -225,7 +225,7 @@ theorem coe_of {f : α → β} (hf : IsSemiringHom f) : ⇑(of hf) = f :=
 lean 3 declaration is
   forall {α : Type.{u1}} {β : Type.{u2}} [rα : Semiring.{u1} α] [rβ : Semiring.{u2} β] (f : RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)), IsSemiringHom.{u1, u2} α β rα rβ (coeFn.{max (succ u1) (succ u2), max (succ u1) (succ u2)} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) (fun (_x : RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) => α -> β) (RingHom.hasCoeToFun.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) f)
 but is expected to have type
-  forall {α : Type.{u1}} {β : Type.{u2}} {rα : Semiring.{u1} α} {rβ : Semiring.{u2} β} (f : RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)), IsSemiringHom.{u1, u2} α β rα rβ (FunLike.coe.{max (succ u1) (succ u2), succ u1, succ u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α (fun (_x : α) => (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2398 : α) => β) _x) (MulHomClass.toFunLike.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonUnitalNonAssocSemiring.toMul.{u1} α (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα))) (NonUnitalNonAssocSemiring.toMul.{u2} β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ))) (NonUnitalRingHomClass.toMulHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα)) (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ)) (RingHomClass.toNonUnitalRingHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ) (RingHom.instRingHomClassRingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ))))) f)
+  forall {α : Type.{u1}} {β : Type.{u2}} {rα : Semiring.{u1} α} {rβ : Semiring.{u2} β} (f : RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)), IsSemiringHom.{u1, u2} α β rα rβ (FunLike.coe.{max (succ u1) (succ u2), succ u1, succ u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α (fun (_x : α) => (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2372 : α) => β) _x) (MulHomClass.toFunLike.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonUnitalNonAssocSemiring.toMul.{u1} α (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα))) (NonUnitalNonAssocSemiring.toMul.{u2} β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ))) (NonUnitalRingHomClass.toMulHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} α (Semiring.toNonAssocSemiring.{u1} α rα)) (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} β (Semiring.toNonAssocSemiring.{u2} β rβ)) (RingHomClass.toNonUnitalRingHomClass.{max u1 u2, u1, u2} (RingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ)) α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ) (RingHom.instRingHomClassRingHom.{u1, u2} α β (Semiring.toNonAssocSemiring.{u1} α rα) (Semiring.toNonAssocSemiring.{u2} β rβ))))) f)
 Case conversion may be inaccurate. Consider using '#align ring_hom.to_is_semiring_hom RingHom.to_isSemiringHomₓ'. -/
 theorem to_isSemiringHom (f : α →+* β) : IsSemiringHom f :=
   { map_zero := f.map_zero
@@ -240,7 +240,7 @@ end
 lean 3 declaration is
   forall {α : Type.{u1}} {γ : Type.{u2}} [_inst_1 : Ring.{u1} α] [_inst_2 : Ring.{u2} γ] (g : RingHom.{u1, u2} α γ (NonAssocRing.toNonAssocSemiring.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u2} γ (Ring.toNonAssocRing.{u2} γ _inst_2))), IsRingHom.{u1, u2} α γ _inst_1 _inst_2 (coeFn.{max (succ u1) (succ u2), max (succ u1) (succ u2)} (RingHom.{u1, u2} α γ (NonAssocRing.toNonAssocSemiring.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u2} γ (Ring.toNonAssocRing.{u2} γ _inst_2))) (fun (_x : RingHom.{u1, u2} α γ (NonAssocRing.toNonAssocSemiring.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u2} γ (Ring.toNonAssocRing.{u2} γ _inst_2))) => α -> γ) (RingHom.hasCoeToFun.{u1, u2} α γ (NonAssocRing.toNonAssocSemiring.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u2} γ (Ring.toNonAssocRing.{u2} γ _inst_2))) g)
 but is expected to have type
-  forall {α : Type.{u2}} {γ : Type.{u1}} [_inst_1 : Ring.{u2} α] [_inst_2 : Ring.{u1} γ] (g : RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))), IsRingHom.{u2, u1} α γ _inst_1 _inst_2 (FunLike.coe.{max (succ u2) (succ u1), succ u2, succ u1} (RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) α (fun (_x : α) => (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2398 : α) => γ) _x) (MulHomClass.toFunLike.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) α γ (NonUnitalNonAssocSemiring.toMul.{u2} α (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} α (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)))) (NonUnitalNonAssocSemiring.toMul.{u1} γ (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} γ (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2)))) (NonUnitalRingHomClass.toMulHomClass.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) α γ (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} α (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1))) (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} γ (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) (RingHomClass.toNonUnitalRingHomClass.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2)) (RingHom.instRingHomClassRingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2)))))) g)
+  forall {α : Type.{u2}} {γ : Type.{u1}} [_inst_1 : Ring.{u2} α] [_inst_2 : Ring.{u1} γ] (g : RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))), IsRingHom.{u2, u1} α γ _inst_1 _inst_2 (FunLike.coe.{max (succ u2) (succ u1), succ u2, succ u1} (RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) α (fun (_x : α) => (fun (x._@.Mathlib.Algebra.Hom.Group._hyg.2372 : α) => γ) _x) (MulHomClass.toFunLike.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) α γ (NonUnitalNonAssocSemiring.toMul.{u2} α (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} α (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)))) (NonUnitalNonAssocSemiring.toMul.{u1} γ (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} γ (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2)))) (NonUnitalRingHomClass.toMulHomClass.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) α γ (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u2} α (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1))) (NonAssocSemiring.toNonUnitalNonAssocSemiring.{u1} γ (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) (RingHomClass.toNonUnitalRingHomClass.{max u2 u1, u2, u1} (RingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2))) α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2)) (RingHom.instRingHomClassRingHom.{u2, u1} α γ (NonAssocRing.toNonAssocSemiring.{u2} α (Ring.toNonAssocRing.{u2} α _inst_1)) (NonAssocRing.toNonAssocSemiring.{u1} γ (Ring.toNonAssocRing.{u1} γ _inst_2)))))) g)
 Case conversion may be inaccurate. Consider using '#align ring_hom.to_is_ring_hom RingHom.to_isRingHomₓ'. -/
 theorem to_isRingHom {α γ} [Ring α] [Ring γ] (g : α →+* γ) : IsRingHom g :=
   IsRingHom.of_semiring g.to_isSemiringHom

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

Empty lines were removed by executing the following Python script twice

import os
import re


# Loop through each file in the repository
for dir_path, dirs, files in os.walk('.'):
  for filename in files:
    if filename.endswith('.lean'):
      file_path = os.path.join(dir_path, filename)

      # Open the file and read its contents
      with open(file_path, 'r') as file:
        content = file.read()

      # Use a regular expression to replace sequences of "variable" lines separated by empty lines
      # with sequences without empty lines
      modified_content = re.sub(r'(variable.*\n)\n(variable(?! .* in))', r'\1\2', content)

      # Write the modified content back to the file
      with open(file_path, 'w') as file:
        file.write(modified_content)

@@ -48,7 +48,6 @@ structure IsSemiringHom {α : Type u} {β : Type v} [Semiring α] [Semiring β]
 namespace IsSemiringHom
 
 variable {β : Type v} [Semiring α] [Semiring β]
-
 variable {f : α → β} (hf : IsSemiringHom f) {x y : α}
 
 /-- The identity map is a semiring homomorphism. -/

This PR accompanies #11246, squeezing some non-terminal simps highlighted by the linter until I decided to stop!

@@ -123,9 +123,9 @@ theorem id : IsRingHom (@id α) := by refine' { .. } <;> intros <;> rfl
 -- see Note [no instance on morphisms]
 /-- The composition of two ring homomorphisms is a ring homomorphism. -/
 theorem comp (hf : IsRingHom f) {γ} [Ring γ] {g : β → γ} (hg : IsRingHom g) : IsRingHom (g ∘ f) :=
-  { map_add := fun x y => by simp [map_add hf]; rw [map_add hg]
-    map_mul := fun x y => by simp [map_mul hf]; rw [map_mul hg]
-    map_one := by simp [map_one hf]; exact map_one hg }
+  { map_add := fun x y => by simp only [Function.comp_apply, map_add hf, map_add hg]
+    map_mul := fun x y => by simp only [Function.comp_apply, map_mul hf, map_mul hg]
+    map_one := by simp only [Function.comp_apply, map_one hf, map_one hg] }
 #align is_ring_hom.comp IsRingHom.comp
 
 /-- A ring homomorphism is also a semiring homomorphism. -/

• depends on: #5966

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

@@ -2,14 +2,11 @@
 Copyright (c) 2020 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 deprecated.ring
-! leanprover-community/mathlib commit 5a3e819569b0f12cbec59d740a2613018e7b8eec
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathlib.Deprecated.Group
 
+#align_import deprecated.ring from "leanprover-community/mathlib"@"5a3e819569b0f12cbec59d740a2613018e7b8eec"
+
 /-!
 # Unbundled semiring and ring homomorphisms (deprecated)
 

This PR fixes two things:

• Most align statements for definitions and theorems and instances that are separated by two newlines from the relevant declaration (s/\n\n#align/\n#align). This is often seen in the mathport output after ending calc blocks.
• All remaining more-than-one-line #align statements. (This was needed for a script I wrote for #3630.)

@@ -105,7 +105,6 @@ theorem map_zero (hf : IsRingHom f) : f 0 = 0 :=
   calc
     f 0 = f (0 + 0) - f 0 := by rw [hf.map_add]; simp
     _ = 0 := by simp
-
 #align is_ring_hom.map_zero IsRingHom.map_zero
 
 /-- Ring homomorphisms preserve additive inverses. -/
@@ -113,7 +112,6 @@ theorem map_neg (hf : IsRingHom f) : f (-x) = -f x :=
   calc
     f (-x) = f (-x + x) - f x := by rw [hf.map_add]; simp
     _ = -f x := by simp [hf.map_zero]
-
 #align is_ring_hom.map_neg IsRingHom.map_neg
 
 /-- Ring homomorphisms preserve subtraction. -/