algebra.ring.regular | Mathlib porting status

Changes since the initial port

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

Changes in mathlib3

2f3994e1

(last sync)

a47cda96

refactor(algebra/group_with_zero/defs): use is_*cancel_mul_zero (#17963)

Diff

@@ -71,18 +71,12 @@ section is_domain
 @[priority 100] -- see Note [lower instance priority]
 instance is_domain.to_cancel_monoid_with_zero [semiring α] [is_domain α] :
   cancel_monoid_with_zero α :=
-{ mul_left_cancel_of_ne_zero := λ a b c ha h,
-    is_cancel_mul_zero.mul_left_cancel_of_ne_zero ha h,
-  mul_right_cancel_of_ne_zero := λ a b c ha h,
-    is_cancel_mul_zero.mul_right_cancel_of_ne_zero ha h,
-  .. semiring.to_monoid_with_zero α }
+{ .. semiring.to_monoid_with_zero α, .. ‹is_domain α› }
 
 variables [comm_semiring α] [is_domain α]
 
 @[priority 100] -- see Note [lower instance priority]
 instance is_domain.to_cancel_comm_monoid_with_zero : cancel_comm_monoid_with_zero α :=
-{ mul_left_cancel_of_ne_zero := λ a b c ha H, is_domain.mul_left_cancel_of_ne_zero ha H,
-  mul_right_cancel_of_ne_zero := λ a b c hb H, is_domain.mul_right_cancel_of_ne_zero hb H,
-  .. (infer_instance : comm_semiring α) }
+{ .. ‹comm_semiring α›, .. ‹is_domain α› }
 
 end is_domain

12d63a7f

feat(ring_theory.integral_domain): add exists_eq_pow_of_mul_eq_pow_of_coprime (#17877)

We add exists_eq_pow_of_mul_eq_pow_of_coprime: this is done for semirings, in order to apply to ideal R for a Dedekind domain R.

Corresponding mathlib4 PR [#928](https://github.com/leanprover-community/mathlib4/pull/928).

Diff

@@ -69,17 +69,20 @@ def no_zero_divisors.to_cancel_comm_monoid_with_zero [comm_ring α] [no_zero_div
 section is_domain
 
 @[priority 100] -- see Note [lower instance priority]
-instance is_domain.to_cancel_monoid_with_zero [ring α] [is_domain α] : cancel_monoid_with_zero α :=
+instance is_domain.to_cancel_monoid_with_zero [semiring α] [is_domain α] :
+  cancel_monoid_with_zero α :=
 { mul_left_cancel_of_ne_zero := λ a b c ha h,
     is_cancel_mul_zero.mul_left_cancel_of_ne_zero ha h,
   mul_right_cancel_of_ne_zero := λ a b c ha h,
     is_cancel_mul_zero.mul_right_cancel_of_ne_zero ha h,
   .. semiring.to_monoid_with_zero α }
 
-variables [comm_ring α] [is_domain α]
+variables [comm_semiring α] [is_domain α]
 
 @[priority 100] -- see Note [lower instance priority]
 instance is_domain.to_cancel_comm_monoid_with_zero : cancel_comm_monoid_with_zero α :=
-no_zero_divisors.to_cancel_comm_monoid_with_zero
+{ mul_left_cancel_of_ne_zero := λ a b c ha H, is_domain.mul_left_cancel_of_ne_zero ha H,
+  mul_right_cancel_of_ne_zero := λ a b c hb H, is_domain.mul_right_cancel_of_ne_zero hb H,
+  .. (infer_instance : comm_semiring α) }
 
 end is_domain

b1d911ac

chore(algebra/ring/defs): refactor is_domain (#17721)

Refactor the definiton of is_domain to use is_cancel_mul_zero instead of no_zero_divisors. This is the correct property for a semiring (to do in a future refactor).

Corresponding mathlib4 PR https://github.com/leanprover-community/mathlib4/pull/799.

depends on #17716

Diff

@@ -70,7 +70,11 @@ section is_domain
 
 @[priority 100] -- see Note [lower instance priority]
 instance is_domain.to_cancel_monoid_with_zero [ring α] [is_domain α] : cancel_monoid_with_zero α :=
-no_zero_divisors.to_cancel_monoid_with_zero
+{ mul_left_cancel_of_ne_zero := λ a b c ha h,
+    is_cancel_mul_zero.mul_left_cancel_of_ne_zero ha h,
+  mul_right_cancel_of_ne_zero := λ a b c ha h,
+    is_cancel_mul_zero.mul_right_cancel_of_ne_zero ha h,
+  .. semiring.to_monoid_with_zero α }
 
 variables [comm_ring α] [is_domain α]

70d50ecf

(first ported)

Changes in mathlib3port

mathlib3

mathlib3port

448144f7

bump to nightly-2023-09-24-06

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

5655435f

Diff

@@ -3,8 +3,8 @@ Copyright (c) 2014 Jeremy Avigad. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Jeremy Avigad, Leonardo de Moura, Floris van Doorn, Yury Kudryashov, Neil Strickland
 -/
-import Mathbin.Algebra.Regular.Basic
-import Mathbin.Algebra.Ring.Defs
+import Algebra.Regular.Basic
+import Algebra.Ring.Defs
 
 #align_import algebra.ring.regular from "leanprover-community/mathlib"@"448144f7ae193a8990cb7473c9e9a01990f64ac7"

448144f7

bump to nightly-2023-08-17-09

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

60285dcc

Diff

@@ -44,9 +44,9 @@ theorem isRightRegular_of_non_zero_divisor [NonUnitalNonAssocRing α] (k : α)
 theorem isRegular_of_ne_zero' [NonUnitalNonAssocRing α] [NoZeroDivisors α] {k : α} (hk : k ≠ 0) :
     IsRegular k :=
   ⟨isLeftRegular_of_non_zero_divisor k fun x h =>
-      (NoZeroDivisors.eq_zero_or_eq_zero_of_mul_eq_zero h).resolve_left hk,
+      (NoZeroDivisors.eq_zero_or_eq_zero_of_hMul_eq_zero h).resolve_left hk,
     isRightRegular_of_non_zero_divisor k fun x h =>
-      (NoZeroDivisors.eq_zero_or_eq_zero_of_mul_eq_zero h).resolve_right hk⟩
+      (NoZeroDivisors.eq_zero_or_eq_zero_of_hMul_eq_zero h).resolve_right hk⟩
 #align is_regular_of_ne_zero' isRegular_of_ne_zero'
 -/
 
@@ -67,9 +67,9 @@ def NoZeroDivisors.toCancelMonoidWithZero [Ring α] [NoZeroDivisors α] : Cancel
     (by infer_instance :
       MonoidWithZero
         α) with
-    mul_left_cancel_of_ne_zero := fun a b c ha =>
+    hMul_left_cancel_of_ne_zero := fun a b c ha =>
       @IsRegular.left _ _ _ (isRegular_of_ne_zero' ha) _ _
-    mul_right_cancel_of_ne_zero := fun a b c hb =>
+    hMul_right_cancel_of_ne_zero := fun a b c hb =>
       @IsRegular.right _ _ _ (isRegular_of_ne_zero' hb) _ _ }
 #align no_zero_divisors.to_cancel_monoid_with_zero NoZeroDivisors.toCancelMonoidWithZero
 -/

448144f7

bump to nightly-2023-07-20-09

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

9c56d0dd

Diff

@@ -2,15 +2,12 @@
 Copyright (c) 2014 Jeremy Avigad. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Jeremy Avigad, Leonardo de Moura, Floris van Doorn, Yury Kudryashov, Neil Strickland
-
-! This file was ported from Lean 3 source module algebra.ring.regular
-! leanprover-community/mathlib commit 448144f7ae193a8990cb7473c9e9a01990f64ac7
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathbin.Algebra.Regular.Basic
 import Mathbin.Algebra.Ring.Defs
 
+#align_import algebra.ring.regular from "leanprover-community/mathlib"@"448144f7ae193a8990cb7473c9e9a01990f64ac7"
+
 /-!
 # Lemmas about regular elements in rings.

448144f7

bump to nightly-2023-06-13-21

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

829520ac

Diff

@@ -21,6 +21,7 @@ import Mathbin.Algebra.Ring.Defs
 
 variable {α : Type _}
 
+#print isLeftRegular_of_non_zero_divisor /-
 /-- Left `mul` by a `k : α` over `[ring α]` is injective, if `k` is not a zero divisor.
 The typeclass that restricts all terms of `α` to have this property is `no_zero_divisors`. -/
 theorem isLeftRegular_of_non_zero_divisor [NonUnitalNonAssocRing α] (k : α)
@@ -29,7 +30,9 @@ theorem isLeftRegular_of_non_zero_divisor [NonUnitalNonAssocRing α] (k : α)
   refine' fun x y (h' : k * x = k * y) => sub_eq_zero.mp (h _ _)
   rw [mul_sub, sub_eq_zero, h']
 #align is_left_regular_of_non_zero_divisor isLeftRegular_of_non_zero_divisor
+-/
 
+#print isRightRegular_of_non_zero_divisor /-
 /-- Right `mul` by a `k : α` over `[ring α]` is injective, if `k` is not a zero divisor.
 The typeclass that restricts all terms of `α` to have this property is `no_zero_divisors`. -/
 theorem isRightRegular_of_non_zero_divisor [NonUnitalNonAssocRing α] (k : α)
@@ -38,7 +41,9 @@ theorem isRightRegular_of_non_zero_divisor [NonUnitalNonAssocRing α] (k : α)
   refine' fun x y (h' : x * k = y * k) => sub_eq_zero.mp (h _ _)
   rw [sub_mul, sub_eq_zero, h']
 #align is_right_regular_of_non_zero_divisor isRightRegular_of_non_zero_divisor
+-/
 
+#print isRegular_of_ne_zero' /-
 theorem isRegular_of_ne_zero' [NonUnitalNonAssocRing α] [NoZeroDivisors α] {k : α} (hk : k ≠ 0) :
     IsRegular k :=
   ⟨isLeftRegular_of_non_zero_divisor k fun x h =>
@@ -46,12 +51,16 @@ theorem isRegular_of_ne_zero' [NonUnitalNonAssocRing α] [NoZeroDivisors α] {k
     isRightRegular_of_non_zero_divisor k fun x h =>
       (NoZeroDivisors.eq_zero_or_eq_zero_of_mul_eq_zero h).resolve_right hk⟩
 #align is_regular_of_ne_zero' isRegular_of_ne_zero'
+-/
 
+#print isRegular_iff_ne_zero' /-
 theorem isRegular_iff_ne_zero' [Nontrivial α] [NonUnitalNonAssocRing α] [NoZeroDivisors α] {k : α} :
     IsRegular k ↔ k ≠ 0 :=
   ⟨fun h => by rintro rfl; exact not_not.mpr h.left not_isLeftRegular_zero, isRegular_of_ne_zero'⟩
 #align is_regular_iff_ne_zero' isRegular_iff_ne_zero'
+-/
 
+#print NoZeroDivisors.toCancelMonoidWithZero /-
 /-- A ring with no zero divisors is a `cancel_monoid_with_zero`.
 
 Note this is not an instance as it forms a typeclass loop. -/
@@ -66,7 +75,9 @@ def NoZeroDivisors.toCancelMonoidWithZero [Ring α] [NoZeroDivisors α] : Cancel
     mul_right_cancel_of_ne_zero := fun a b c hb =>
       @IsRegular.right _ _ _ (isRegular_of_ne_zero' hb) _ _ }
 #align no_zero_divisors.to_cancel_monoid_with_zero NoZeroDivisors.toCancelMonoidWithZero
+-/
 
+#print NoZeroDivisors.toCancelCommMonoidWithZero /-
 /-- A commutative ring with no zero divisors is a `cancel_comm_monoid_with_zero`.
 
 Note this is not an instance as it forms a typeclass loop. -/
@@ -75,6 +86,7 @@ def NoZeroDivisors.toCancelCommMonoidWithZero [CommRing α] [NoZeroDivisors α]
     CancelCommMonoidWithZero α :=
   { NoZeroDivisors.toCancelMonoidWithZero, (by infer_instance : CommMonoidWithZero α) with }
 #align no_zero_divisors.to_cancel_comm_monoid_with_zero NoZeroDivisors.toCancelCommMonoidWithZero
+-/
 
 section IsDomain

448144f7

bump to nightly-2023-05-28-06

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

ba5d8b97

Diff

@@ -21,12 +21,6 @@ import Mathbin.Algebra.Ring.Defs
 
 variable {α : Type _}
 
-/- warning: is_left_regular_of_non_zero_divisor -> isLeftRegular_of_non_zero_divisor is a dubious translation:
-lean 3 declaration is
-  forall {α : Type.{u1}} [_inst_1 : NonUnitalNonAssocRing.{u1} α] (k : α), (forall (x : α), (Eq.{succ u1} α (HMul.hMul.{u1, u1, u1} α α α (instHMul.{u1} α (Distrib.toHasMul.{u1} α (NonUnitalNonAssocSemiring.toDistrib.{u1} α (NonUnitalNonAssocRing.toNonUnitalNonAssocSemiring.{u1} α _inst_1)))) k x) (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 _inst_1))))))) -> (Eq.{succ u1} α x (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 _inst_1)))))))) -> (IsLeftRegular.{u1} α (Distrib.toHasMul.{u1} α (NonUnitalNonAssocSemiring.toDistrib.{u1} α (NonUnitalNonAssocRing.toNonUnitalNonAssocSemiring.{u1} α _inst_1))) k)
-but is expected to have type
-  forall {α : Type.{u1}} [_inst_1 : NonUnitalNonAssocRing.{u1} α] (k : α), (forall (x : α), (Eq.{succ u1} α (HMul.hMul.{u1, u1, u1} α α α (instHMul.{u1} α (NonUnitalNonAssocRing.toMul.{u1} α _inst_1)) k x) (OfNat.ofNat.{u1} α 0 (Zero.toOfNat0.{u1} α (MulZeroClass.toZero.{u1} α (NonUnitalNonAssocSemiring.toMulZeroClass.{u1} α (NonUnitalNonAssocRing.toNonUnitalNonAssocSemiring.{u1} α _inst_1)))))) -> (Eq.{succ u1} α x (OfNat.ofNat.{u1} α 0 (Zero.toOfNat0.{u1} α (MulZeroClass.toZero.{u1} α (NonUnitalNonAssocSemiring.toMulZeroClass.{u1} α (NonUnitalNonAssocRing.toNonUnitalNonAssocSemiring.{u1} α _inst_1))))))) -> (IsLeftRegular.{u1} α (NonUnitalNonAssocRing.toMul.{u1} α _inst_1) k)
-Case conversion may be inaccurate. Consider using '#align is_left_regular_of_non_zero_divisor isLeftRegular_of_non_zero_divisorₓ'. -/
 /-- Left `mul` by a `k : α` over `[ring α]` is injective, if `k` is not a zero divisor.
 The typeclass that restricts all terms of `α` to have this property is `no_zero_divisors`. -/
 theorem isLeftRegular_of_non_zero_divisor [NonUnitalNonAssocRing α] (k : α)
@@ -36,12 +30,6 @@ theorem isLeftRegular_of_non_zero_divisor [NonUnitalNonAssocRing α] (k : α)
   rw [mul_sub, sub_eq_zero, h']
 #align is_left_regular_of_non_zero_divisor isLeftRegular_of_non_zero_divisor
 
-/- warning: is_right_regular_of_non_zero_divisor -> isRightRegular_of_non_zero_divisor is a dubious translation:
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-but is expected to have type
-  forall {α : Type.{u1}} [_inst_1 : NonUnitalNonAssocRing.{u1} α] (k : α), (forall (x : α), (Eq.{succ u1} α (HMul.hMul.{u1, u1, u1} α α α (instHMul.{u1} α (NonUnitalNonAssocRing.toMul.{u1} α _inst_1)) x k) (OfNat.ofNat.{u1} α 0 (Zero.toOfNat0.{u1} α (MulZeroClass.toZero.{u1} α (NonUnitalNonAssocSemiring.toMulZeroClass.{u1} α (NonUnitalNonAssocRing.toNonUnitalNonAssocSemiring.{u1} α _inst_1)))))) -> (Eq.{succ u1} α x (OfNat.ofNat.{u1} α 0 (Zero.toOfNat0.{u1} α (MulZeroClass.toZero.{u1} α (NonUnitalNonAssocSemiring.toMulZeroClass.{u1} α (NonUnitalNonAssocRing.toNonUnitalNonAssocSemiring.{u1} α _inst_1))))))) -> (IsRightRegular.{u1} α (NonUnitalNonAssocRing.toMul.{u1} α _inst_1) k)
-Case conversion may be inaccurate. Consider using '#align is_right_regular_of_non_zero_divisor isRightRegular_of_non_zero_divisorₓ'. -/
 /-- Right `mul` by a `k : α` over `[ring α]` is injective, if `k` is not a zero divisor.
 The typeclass that restricts all terms of `α` to have this property is `no_zero_divisors`. -/
 theorem isRightRegular_of_non_zero_divisor [NonUnitalNonAssocRing α] (k : α)
@@ -51,12 +39,6 @@ theorem isRightRegular_of_non_zero_divisor [NonUnitalNonAssocRing α] (k : α)
   rw [sub_mul, sub_eq_zero, h']
 #align is_right_regular_of_non_zero_divisor isRightRegular_of_non_zero_divisor
 
-/- warning: is_regular_of_ne_zero' -> isRegular_of_ne_zero' is a dubious translation:
-lean 3 declaration is
-  forall {α : Type.{u1}} [_inst_1 : NonUnitalNonAssocRing.{u1} α] [_inst_2 : NoZeroDivisors.{u1} α (Distrib.toHasMul.{u1} α (NonUnitalNonAssocSemiring.toDistrib.{u1} α (NonUnitalNonAssocRing.toNonUnitalNonAssocSemiring.{u1} α _inst_1))) (MulZeroClass.toHasZero.{u1} α (NonUnitalNonAssocSemiring.toMulZeroClass.{u1} α (NonUnitalNonAssocRing.toNonUnitalNonAssocSemiring.{u1} α _inst_1)))] {k : α}, (Ne.{succ u1} α k (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 _inst_1))))))) -> (IsRegular.{u1} α (Distrib.toHasMul.{u1} α (NonUnitalNonAssocSemiring.toDistrib.{u1} α (NonUnitalNonAssocRing.toNonUnitalNonAssocSemiring.{u1} α _inst_1))) k)
-but is expected to have type
-  forall {α : Type.{u1}} [_inst_1 : NonUnitalNonAssocRing.{u1} α] [_inst_2 : NoZeroDivisors.{u1} α (NonUnitalNonAssocRing.toMul.{u1} α _inst_1) (MulZeroClass.toZero.{u1} α (NonUnitalNonAssocSemiring.toMulZeroClass.{u1} α (NonUnitalNonAssocRing.toNonUnitalNonAssocSemiring.{u1} α _inst_1)))] {k : α}, (Ne.{succ u1} α k (OfNat.ofNat.{u1} α 0 (Zero.toOfNat0.{u1} α (MulZeroClass.toZero.{u1} α (NonUnitalNonAssocSemiring.toMulZeroClass.{u1} α (NonUnitalNonAssocRing.toNonUnitalNonAssocSemiring.{u1} α _inst_1)))))) -> (IsRegular.{u1} α (NonUnitalNonAssocRing.toMul.{u1} α _inst_1) k)
-Case conversion may be inaccurate. Consider using '#align is_regular_of_ne_zero' isRegular_of_ne_zero'ₓ'. -/
 theorem isRegular_of_ne_zero' [NonUnitalNonAssocRing α] [NoZeroDivisors α] {k : α} (hk : k ≠ 0) :
     IsRegular k :=
   ⟨isLeftRegular_of_non_zero_divisor k fun x h =>
@@ -65,23 +47,11 @@ theorem isRegular_of_ne_zero' [NonUnitalNonAssocRing α] [NoZeroDivisors α] {k
       (NoZeroDivisors.eq_zero_or_eq_zero_of_mul_eq_zero h).resolve_right hk⟩
 #align is_regular_of_ne_zero' isRegular_of_ne_zero'
 
-/- warning: is_regular_iff_ne_zero' -> isRegular_iff_ne_zero' is a dubious translation:
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-  forall {α : Type.{u1}} [_inst_1 : Nontrivial.{u1} α] [_inst_2 : NonUnitalNonAssocRing.{u1} α] [_inst_3 : NoZeroDivisors.{u1} α (Distrib.toHasMul.{u1} α (NonUnitalNonAssocSemiring.toDistrib.{u1} α (NonUnitalNonAssocRing.toNonUnitalNonAssocSemiring.{u1} α _inst_2))) (MulZeroClass.toHasZero.{u1} α (NonUnitalNonAssocSemiring.toMulZeroClass.{u1} α (NonUnitalNonAssocRing.toNonUnitalNonAssocSemiring.{u1} α _inst_2)))] {k : α}, Iff (IsRegular.{u1} α (Distrib.toHasMul.{u1} α (NonUnitalNonAssocSemiring.toDistrib.{u1} α (NonUnitalNonAssocRing.toNonUnitalNonAssocSemiring.{u1} α _inst_2))) k) (Ne.{succ u1} α k (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 _inst_2)))))))
-but is expected to have type
-  forall {α : Type.{u1}} [_inst_1 : Nontrivial.{u1} α] [_inst_2 : NonUnitalNonAssocRing.{u1} α] [_inst_3 : NoZeroDivisors.{u1} α (NonUnitalNonAssocRing.toMul.{u1} α _inst_2) (MulZeroClass.toZero.{u1} α (NonUnitalNonAssocSemiring.toMulZeroClass.{u1} α (NonUnitalNonAssocRing.toNonUnitalNonAssocSemiring.{u1} α _inst_2)))] {k : α}, Iff (IsRegular.{u1} α (NonUnitalNonAssocRing.toMul.{u1} α _inst_2) k) (Ne.{succ u1} α k (OfNat.ofNat.{u1} α 0 (Zero.toOfNat0.{u1} α (MulZeroClass.toZero.{u1} α (NonUnitalNonAssocSemiring.toMulZeroClass.{u1} α (NonUnitalNonAssocRing.toNonUnitalNonAssocSemiring.{u1} α _inst_2))))))
-Case conversion may be inaccurate. Consider using '#align is_regular_iff_ne_zero' isRegular_iff_ne_zero'ₓ'. -/
 theorem isRegular_iff_ne_zero' [Nontrivial α] [NonUnitalNonAssocRing α] [NoZeroDivisors α] {k : α} :
     IsRegular k ↔ k ≠ 0 :=
   ⟨fun h => by rintro rfl; exact not_not.mpr h.left not_isLeftRegular_zero, isRegular_of_ne_zero'⟩
 #align is_regular_iff_ne_zero' isRegular_iff_ne_zero'
 
-/- warning: no_zero_divisors.to_cancel_monoid_with_zero -> NoZeroDivisors.toCancelMonoidWithZero is a dubious translation:
-lean 3 declaration is
-  forall {α : Type.{u1}} [_inst_1 : Ring.{u1} α] [_inst_2 : NoZeroDivisors.{u1} α (Distrib.toHasMul.{u1} α (Ring.toDistrib.{u1} α _inst_1)) (MulZeroClass.toHasZero.{u1} α (NonUnitalNonAssocSemiring.toMulZeroClass.{u1} α (NonUnitalNonAssocRing.toNonUnitalNonAssocSemiring.{u1} α (NonAssocRing.toNonUnitalNonAssocRing.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1)))))], CancelMonoidWithZero.{u1} α
-but is expected to have type
-  forall {α : Type.{u1}} [_inst_1 : Ring.{u1} α] [_inst_2 : NoZeroDivisors.{u1} α (NonUnitalNonAssocRing.toMul.{u1} α (NonAssocRing.toNonUnitalNonAssocRing.{u1} α (Ring.toNonAssocRing.{u1} α _inst_1))) (MonoidWithZero.toZero.{u1} α (Semiring.toMonoidWithZero.{u1} α (Ring.toSemiring.{u1} α _inst_1)))], CancelMonoidWithZero.{u1} α
-Case conversion may be inaccurate. Consider using '#align no_zero_divisors.to_cancel_monoid_with_zero NoZeroDivisors.toCancelMonoidWithZeroₓ'. -/
 /-- A ring with no zero divisors is a `cancel_monoid_with_zero`.
 
 Note this is not an instance as it forms a typeclass loop. -/
@@ -97,12 +67,6 @@ def NoZeroDivisors.toCancelMonoidWithZero [Ring α] [NoZeroDivisors α] : Cancel
       @IsRegular.right _ _ _ (isRegular_of_ne_zero' hb) _ _ }
 #align no_zero_divisors.to_cancel_monoid_with_zero NoZeroDivisors.toCancelMonoidWithZero
 
-/- warning: no_zero_divisors.to_cancel_comm_monoid_with_zero -> NoZeroDivisors.toCancelCommMonoidWithZero is a dubious translation:
-lean 3 declaration is
-  forall {α : Type.{u1}} [_inst_1 : CommRing.{u1} α] [_inst_2 : NoZeroDivisors.{u1} α (Distrib.toHasMul.{u1} α (Ring.toDistrib.{u1} α (CommRing.toRing.{u1} α _inst_1))) (MulZeroClass.toHasZero.{u1} α (NonUnitalNonAssocSemiring.toMulZeroClass.{u1} α (NonUnitalNonAssocRing.toNonUnitalNonAssocSemiring.{u1} α (NonAssocRing.toNonUnitalNonAssocRing.{u1} α (Ring.toNonAssocRing.{u1} α (CommRing.toRing.{u1} α _inst_1))))))], CancelCommMonoidWithZero.{u1} α
-but is expected to have type
-  forall {α : Type.{u1}} [_inst_1 : CommRing.{u1} α] [_inst_2 : NoZeroDivisors.{u1} α (NonUnitalNonAssocRing.toMul.{u1} α (NonAssocRing.toNonUnitalNonAssocRing.{u1} α (Ring.toNonAssocRing.{u1} α (CommRing.toRing.{u1} α _inst_1)))) (CommMonoidWithZero.toZero.{u1} α (CommSemiring.toCommMonoidWithZero.{u1} α (CommRing.toCommSemiring.{u1} α _inst_1)))], CancelCommMonoidWithZero.{u1} α
-Case conversion may be inaccurate. Consider using '#align no_zero_divisors.to_cancel_comm_monoid_with_zero NoZeroDivisors.toCancelCommMonoidWithZeroₓ'. -/
 /-- A commutative ring with no zero divisors is a `cancel_comm_monoid_with_zero`.
 
 Note this is not an instance as it forms a typeclass loop. -/

448144f7

bump to nightly-2023-05-28-04

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

6797a637

Diff

@@ -73,9 +73,7 @@ but is expected to have type
 Case conversion may be inaccurate. Consider using '#align is_regular_iff_ne_zero' isRegular_iff_ne_zero'ₓ'. -/
 theorem isRegular_iff_ne_zero' [Nontrivial α] [NonUnitalNonAssocRing α] [NoZeroDivisors α] {k : α} :
     IsRegular k ↔ k ≠ 0 :=
-  ⟨fun h => by
-    rintro rfl
-    exact not_not.mpr h.left not_isLeftRegular_zero, isRegular_of_ne_zero'⟩
+  ⟨fun h => by rintro rfl; exact not_not.mpr h.left not_isLeftRegular_zero, isRegular_of_ne_zero'⟩
 #align is_regular_iff_ne_zero' isRegular_iff_ne_zero'
 
 /- warning: no_zero_divisors.to_cancel_monoid_with_zero -> NoZeroDivisors.toCancelMonoidWithZero is a dubious translation:

448144f7

bump to nightly-2023-02-21-16

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

1107b979

Changes in mathlib4

mathlib3

mathlib4

2f3994e1

chore: banish Type _ and Sort _ (#6499)

We remove all possible occurences of Type _ and Sort _ in favor of Type* and Sort*.

This has nice performance benefits.

32de3f67

Diff

@@ -13,7 +13,7 @@ import Mathlib.Algebra.Ring.Defs
 -/
 
 
-variable {α : Type _}
+variable {α : Type*}
 
 /-- Left `Mul` by a `k : α` over `[Ring α]` is injective, if `k` is not a zero divisor.
 The typeclass that restricts all terms of `α` to have this property is `NoZeroDivisors`. -/

2f3994e1

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

depends on: #5966

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

89aa3a3b

Diff

@@ -2,15 +2,12 @@
 Copyright (c) 2014 Jeremy Avigad. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Jeremy Avigad, Leonardo de Moura, Floris van Doorn, Yury Kudryashov, Neil Strickland
-
-! This file was ported from Lean 3 source module algebra.ring.regular
-! leanprover-community/mathlib commit 2f3994e1b117b1e1da49bcfb67334f33460c3ce4
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathlib.Algebra.Regular.Basic
 import Mathlib.Algebra.Ring.Defs
 
+#align_import algebra.ring.regular from "leanprover-community/mathlib"@"2f3994e1b117b1e1da49bcfb67334f33460c3ce4"
+
 /-!
 # Lemmas about regular elements in rings.
 -/

2f3994e1

refactor: use Is*CancelMulZero (#1137)

This is a Lean 4 version of leanprover-community/mathlib#17963

3bc62129

Diff

@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Jeremy Avigad, Leonardo de Moura, Floris van Doorn, Yury Kudryashov, Neil Strickland
 
 ! This file was ported from Lean 3 source module algebra.ring.regular
-! leanprover-community/mathlib commit 70d50ecfd4900dd6d328da39ab7ebd516abe4025
+! leanprover-community/mathlib commit 2f3994e1b117b1e1da49bcfb67334f33460c3ce4
 ! Please do not edit these lines, except to modify the commit id
 ! if you have ported upstream changes.
 -/
@@ -67,7 +67,7 @@ Note this is not an instance as it forms a typeclass loop. -/
 @[reducible]
 def NoZeroDivisors.toCancelCommMonoidWithZero [CommRing α] [NoZeroDivisors α] :
     CancelCommMonoidWithZero α :=
-  { NoZeroDivisors.toCancelMonoidWithZero, (by infer_instance : CommMonoidWithZero α) with }
+  { NoZeroDivisors.toCancelMonoidWithZero, ‹CommRing α› with }
 #align no_zero_divisors.to_cancel_comm_monoid_with_zero NoZeroDivisors.toCancelCommMonoidWithZero
 
 section IsDomain
@@ -75,16 +75,14 @@ section IsDomain
 -- see Note [lower instance priority]
 instance (priority := 100) IsDomain.toCancelMonoidWithZero [Semiring α] [IsDomain α] :
     CancelMonoidWithZero α :=
-  { mul_left_cancel_of_ne_zero := IsLeftCancelMulZero.mul_left_cancel_of_ne_zero
-    mul_right_cancel_of_ne_zero := IsRightCancelMulZero.mul_right_cancel_of_ne_zero }
+  { }
 #align is_domain.to_cancel_monoid_with_zero IsDomain.toCancelMonoidWithZero
 
 variable [CommSemiring α] [IsDomain α]
 
 -- see Note [lower instance priority]
 instance (priority := 100) IsDomain.toCancelCommMonoidWithZero : CancelCommMonoidWithZero α :=
-  { mul_left_cancel_of_ne_zero := IsLeftCancelMulZero.mul_left_cancel_of_ne_zero
-    mul_right_cancel_of_ne_zero := IsRightCancelMulZero.mul_right_cancel_of_ne_zero }
+  { mul_left_cancel_of_ne_zero := IsLeftCancelMulZero.mul_left_cancel_of_ne_zero }
 #align is_domain.to_cancel_comm_monoid_with_zero IsDomain.toCancelCommMonoidWithZero
 
 end IsDomain

70d50ecf

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

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

f168625e

Diff

@@ -2,6 +2,11 @@
 Copyright (c) 2014 Jeremy Avigad. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Jeremy Avigad, Leonardo de Moura, Floris van Doorn, Yury Kudryashov, Neil Strickland
+
+! This file was ported from Lean 3 source module algebra.ring.regular
+! leanprover-community/mathlib commit 70d50ecfd4900dd6d328da39ab7ebd516abe4025
+! Please do not edit these lines, except to modify the commit id
+! if you have ported upstream changes.
 -/
 import Mathlib.Algebra.Regular.Basic
 import Mathlib.Algebra.Ring.Defs

`algebra.ring.regular` ⟷ `Mathlib.Algebra.Ring.Regular`

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 37

algebra.ring.regular ⟷ Mathlib.Algebra.Ring.Regular

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 37

`algebra.ring.regular` ⟷ `Mathlib.Algebra.Ring.Regular`