logic.unique | 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

c4658a64

(last sync)

Changes in mathlib3port

mathlib3

mathlib3port

448144f7

bump to nightly-2023-11-29-11

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

049e2cad

Diff

@@ -128,11 +128,9 @@ theorem Fin.eq_zero : ∀ n : Fin 1, n = 0
 instance {n : ℕ} : Inhabited (Fin n.succ) :=
   ⟨0⟩
 
-#print inhabitedFinOneAdd /-
 instance inhabitedFinOneAdd (n : ℕ) : Inhabited (Fin (1 + n)) :=
   ⟨⟨0, Nat.zero_lt_one_add n⟩⟩
 #align inhabited_fin_one_add inhabitedFinOneAdd
--/
 
 #print Fin.default_eq_zero /-
 @[simp]
@@ -141,11 +139,9 @@ theorem Fin.default_eq_zero (n : ℕ) : (default : Fin n.succ) = 0 :=
 #align fin.default_eq_zero Fin.default_eq_zero
 -/
 
-#print Fin.unique /-
 instance Fin.unique : Unique (Fin 1) :=
   { Fin.inhabited with uniq := Fin.eq_zero }
 #align fin.unique Fin.unique
--/
 
 namespace Unique

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) 2019 Johan Commelin. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Johan Commelin
 -/
-import Mathbin.Tactic.Basic
-import Mathbin.Logic.IsEmpty
+import Tactic.Basic
+import Logic.IsEmpty
 
 #align_import logic.unique from "leanprover-community/mathlib"@"448144f7ae193a8990cb7473c9e9a01990f64ac7"

448144f7

bump to nightly-2023-07-20-09

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

9c56d0dd

Diff

@@ -2,15 +2,12 @@
 Copyright (c) 2019 Johan Commelin. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Johan Commelin
-
-! This file was ported from Lean 3 source module logic.unique
-! 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.Tactic.Basic
 import Mathbin.Logic.IsEmpty
 
+#align_import logic.unique from "leanprover-community/mathlib"@"448144f7ae193a8990cb7473c9e9a01990f64ac7"
+
 /-!
 # Types with a unique term

448144f7

bump to nightly-2023-06-13-21

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

829520ac

Diff

@@ -239,20 +239,26 @@ theorem Pi.default_apply {β : α → Sort v} [∀ a, Inhabited (β a)] (a : α)
 #align pi.default_apply Pi.default_apply
 -/
 
+#print Pi.unique /-
 instance Pi.unique {β : α → Sort v} [∀ a, Unique (β a)] : Unique (∀ a, β a) :=
   { Pi.inhabited α with uniq := fun f => funext fun x => Unique.eq_default _ }
 #align pi.unique Pi.unique
+-/
 
+#print Pi.uniqueOfIsEmpty /-
 /-- There is a unique function on an empty domain. -/
 instance Pi.uniqueOfIsEmpty [IsEmpty α] (β : α → Sort v) : Unique (∀ a, β a)
     where
   default := isEmptyElim
   uniq f := funext isEmptyElim
 #align pi.unique_of_is_empty Pi.uniqueOfIsEmpty
+-/
 
+#print eq_const_of_unique /-
 theorem eq_const_of_unique [Unique α] (f : α → β) : f = Function.const α (f default) := by ext x;
   rw [Subsingleton.elim x default]
 #align eq_const_of_unique eq_const_of_unique
+-/
 
 #print heq_const_of_unique /-
 theorem heq_const_of_unique [Unique α] {β : α → Sort v} (f : ∀ a, β a) :
@@ -265,17 +271,21 @@ namespace Function
 
 variable {f : α → β}
 
+#print Function.Injective.subsingleton /-
 /-- If the codomain of an injective function is a subsingleton, then the domain
 is a subsingleton as well. -/
 protected theorem Injective.subsingleton (hf : Injective f) [Subsingleton β] : Subsingleton α :=
   ⟨fun x y => hf <| Subsingleton.elim _ _⟩
 #align function.injective.subsingleton Function.Injective.subsingleton
+-/
 
+#print Function.Surjective.subsingleton /-
 /-- If the domain of a surjective function is a subsingleton, then the codomain is a subsingleton as
 well. -/
 protected theorem Surjective.subsingleton [Subsingleton α] (hf : Surjective f) : Subsingleton β :=
   ⟨hf.Forall₂.2 fun x y => congr_arg f <| Subsingleton.elim x y⟩
 #align function.surjective.subsingleton Function.Surjective.subsingleton
+-/
 
 #print Function.Surjective.unique /-
 /-- If the domain of a surjective function is a singleton,
@@ -302,11 +312,13 @@ def Surjective.uniqueOfSurjectiveConst (α : Type _) {β : Type _} (b : β)
 
 end Function
 
+#print Unique.bijective /-
 theorem Unique.bijective {A B} [Unique A] [Unique B] {f : A → B} : Function.Bijective f :=
   by
   rw [Function.bijective_iff_has_inverse]
   refine' ⟨default, _, _⟩ <;> intro x <;> simp
 #align unique.bijective Unique.bijective
+-/
 
 namespace Option

448144f7

bump to nightly-2023-06-01-16

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

b9c87c70

Diff

@@ -76,7 +76,7 @@ theorem unique_iff_exists_unique (α : Sort u) : Nonempty (Unique α) ↔ ∃! a
 theorem unique_subtype_iff_exists_unique {α} (p : α → Prop) :
     Nonempty (Unique (Subtype p)) ↔ ∃! a, p a :=
   ⟨fun ⟨u⟩ => ⟨u.default.1, u.default.2, fun a h => congr_arg Subtype.val (u.uniq ⟨a, h⟩)⟩,
-    fun ⟨a, ha, he⟩ => ⟨⟨⟨⟨a, ha⟩⟩, fun ⟨b, hb⟩ => by congr ; exact he b hb⟩⟩⟩
+    fun ⟨a, ha, he⟩ => ⟨⟨⟨⟨a, ha⟩⟩, fun ⟨b, hb⟩ => by congr; exact he b hb⟩⟩⟩
 #align unique_subtype_iff_exists_unique unique_subtype_iff_exists_unique
 -/

448144f7

bump to nightly-2023-05-28-06

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

ba5d8b97

Diff

@@ -239,22 +239,10 @@ theorem Pi.default_apply {β : α → Sort v} [∀ a, Inhabited (β a)] (a : α)
 #align pi.default_apply Pi.default_apply
 -/
 
-/- warning: pi.unique -> Pi.unique is a dubious translation:
-lean 3 declaration is
-  forall {α : Sort.{u1}} {β : α -> Sort.{u2}} [_inst_1 : forall (a : α), Unique.{u2} (β a)], Unique.{imax u1 u2} (forall (a : α), β a)
-but is expected to have type
-  forall {α : Sort.{u2}} {β : α -> Sort.{u1}} [_inst_1 : forall (a : α), Unique.{u1} (β a)], Unique.{imax u2 u1} (forall (a : α), β a)
-Case conversion may be inaccurate. Consider using '#align pi.unique Pi.uniqueₓ'. -/
 instance Pi.unique {β : α → Sort v} [∀ a, Unique (β a)] : Unique (∀ a, β a) :=
   { Pi.inhabited α with uniq := fun f => funext fun x => Unique.eq_default _ }
 #align pi.unique Pi.unique
 
-/- warning: pi.unique_of_is_empty -> Pi.uniqueOfIsEmpty is a dubious translation:
-lean 3 declaration is
-  forall {α : Sort.{u1}} [_inst_1 : IsEmpty.{u1} α] (β : α -> Sort.{u2}), Unique.{imax u1 u2} (forall (a : α), β a)
-but is expected to have type
-  forall {α : Sort.{u2}} [_inst_1 : IsEmpty.{u2} α] (β : α -> Sort.{u1}), Unique.{imax u2 u1} (forall (a : α), β a)
-Case conversion may be inaccurate. Consider using '#align pi.unique_of_is_empty Pi.uniqueOfIsEmptyₓ'. -/
 /-- There is a unique function on an empty domain. -/
 instance Pi.uniqueOfIsEmpty [IsEmpty α] (β : α → Sort v) : Unique (∀ a, β a)
     where
@@ -262,12 +250,6 @@ instance Pi.uniqueOfIsEmpty [IsEmpty α] (β : α → Sort v) : Unique (∀ a, 
   uniq f := funext isEmptyElim
 #align pi.unique_of_is_empty Pi.uniqueOfIsEmpty
 
-/- warning: eq_const_of_unique -> eq_const_of_unique is a dubious translation:
-lean 3 declaration is
-  forall {α : Sort.{u1}} {β : Sort.{u2}} [_inst_1 : Unique.{u1} α] (f : α -> β), Eq.{imax u1 u2} (α -> β) f (Function.const.{u2, u1} β α (f (Inhabited.default.{u1} α (Unique.inhabited.{u1} α _inst_1))))
-but is expected to have type
-  forall {α : Sort.{u2}} {β : Sort.{u1}} [_inst_1 : Unique.{u2} α] (f : α -> β), Eq.{imax u2 u1} (α -> β) f (Function.const.{u1, u2} β α (f (Inhabited.default.{u2} α (Unique.instInhabited.{u2} α _inst_1))))
-Case conversion may be inaccurate. Consider using '#align eq_const_of_unique eq_const_of_uniqueₓ'. -/
 theorem eq_const_of_unique [Unique α] (f : α → β) : f = Function.const α (f default) := by ext x;
   rw [Subsingleton.elim x default]
 #align eq_const_of_unique eq_const_of_unique
@@ -283,24 +265,12 @@ namespace Function
 
 variable {f : α → β}
 
-/- warning: function.injective.subsingleton -> Function.Injective.subsingleton is a dubious translation:
-lean 3 declaration is
-  forall {α : Sort.{u1}} {β : Sort.{u2}} {f : α -> β}, (Function.Injective.{u1, u2} α β f) -> (forall [_inst_1 : Subsingleton.{u2} β], Subsingleton.{u1} α)
-but is expected to have type
-  forall {α : Sort.{u2}} {β : Sort.{u1}} {f : α -> β}, (Function.Injective.{u2, u1} α β f) -> (forall [_inst_1 : Subsingleton.{u1} β], Subsingleton.{u2} α)
-Case conversion may be inaccurate. Consider using '#align function.injective.subsingleton Function.Injective.subsingletonₓ'. -/
 /-- If the codomain of an injective function is a subsingleton, then the domain
 is a subsingleton as well. -/
 protected theorem Injective.subsingleton (hf : Injective f) [Subsingleton β] : Subsingleton α :=
   ⟨fun x y => hf <| Subsingleton.elim _ _⟩
 #align function.injective.subsingleton Function.Injective.subsingleton
 
-/- warning: function.surjective.subsingleton -> Function.Surjective.subsingleton is a dubious translation:
-lean 3 declaration is
-  forall {α : Sort.{u1}} {β : Sort.{u2}} {f : α -> β} [_inst_1 : Subsingleton.{u1} α], (Function.Surjective.{u1, u2} α β f) -> (Subsingleton.{u2} β)
-but is expected to have type
-  forall {α : Sort.{u2}} {β : Sort.{u1}} {f : α -> β} [_inst_1 : Subsingleton.{u2} α], (Function.Surjective.{u2, u1} α β f) -> (Subsingleton.{u1} β)
-Case conversion may be inaccurate. Consider using '#align function.surjective.subsingleton Function.Surjective.subsingletonₓ'. -/
 /-- If the domain of a surjective function is a subsingleton, then the codomain is a subsingleton as
 well. -/
 protected theorem Surjective.subsingleton [Subsingleton α] (hf : Surjective f) : Subsingleton β :=
@@ -332,12 +302,6 @@ def Surjective.uniqueOfSurjectiveConst (α : Type _) {β : Type _} (b : β)
 
 end Function
 
-/- warning: unique.bijective -> Unique.bijective is a dubious translation:
-lean 3 declaration is
-  forall {A : Sort.{u1}} {B : Sort.{u2}} [_inst_1 : Unique.{u1} A] [_inst_2 : Unique.{u2} B] {f : A -> B}, Function.Bijective.{u1, u2} A B f
-but is expected to have type
-  forall {A : Sort.{u2}} {B : Sort.{u1}} [_inst_1 : Unique.{u2} A] [_inst_2 : Unique.{u1} B] {f : A -> B}, Function.Bijective.{u2, u1} A B f
-Case conversion may be inaccurate. Consider using '#align unique.bijective Unique.bijectiveₓ'. -/
 theorem Unique.bijective {A B} [Unique A] [Unique B] {f : A → B} : Function.Bijective f :=
   by
   rw [Function.bijective_iff_has_inverse]

448144f7

bump to nightly-2023-05-28-04

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

6797a637

Diff

@@ -76,10 +76,7 @@ theorem unique_iff_exists_unique (α : Sort u) : Nonempty (Unique α) ↔ ∃! a
 theorem unique_subtype_iff_exists_unique {α} (p : α → Prop) :
     Nonempty (Unique (Subtype p)) ↔ ∃! a, p a :=
   ⟨fun ⟨u⟩ => ⟨u.default.1, u.default.2, fun a h => congr_arg Subtype.val (u.uniq ⟨a, h⟩)⟩,
-    fun ⟨a, ha, he⟩ =>
-    ⟨⟨⟨⟨a, ha⟩⟩, fun ⟨b, hb⟩ => by
-        congr
-        exact he b hb⟩⟩⟩
+    fun ⟨a, ha, he⟩ => ⟨⟨⟨⟨a, ha⟩⟩, fun ⟨b, hb⟩ => by congr ; exact he b hb⟩⟩⟩
 #align unique_subtype_iff_exists_unique unique_subtype_iff_exists_unique
 -/
 
@@ -223,10 +220,7 @@ end Unique
 theorem unique_iff_subsingleton_and_nonempty (α : Sort u) :
     Nonempty (Unique α) ↔ Subsingleton α ∧ Nonempty α :=
   ⟨fun ⟨u⟩ => by constructor <;> exact inferInstance, fun ⟨hs, hn⟩ =>
-    ⟨by
-      skip
-      inhabit α
-      exact Unique.mk' α⟩⟩
+    ⟨by skip; inhabit α; exact Unique.mk' α⟩⟩
 #align unique_iff_subsingleton_and_nonempty unique_iff_subsingleton_and_nonempty
 -/
 
@@ -274,9 +268,7 @@ lean 3 declaration is
 but is expected to have type
   forall {α : Sort.{u2}} {β : Sort.{u1}} [_inst_1 : Unique.{u2} α] (f : α -> β), Eq.{imax u2 u1} (α -> β) f (Function.const.{u1, u2} β α (f (Inhabited.default.{u2} α (Unique.instInhabited.{u2} α _inst_1))))
 Case conversion may be inaccurate. Consider using '#align eq_const_of_unique eq_const_of_uniqueₓ'. -/
-theorem eq_const_of_unique [Unique α] (f : α → β) : f = Function.const α (f default) :=
-  by
-  ext x
+theorem eq_const_of_unique [Unique α] (f : α → β) : f = Function.const α (f default) := by ext x;
   rw [Subsingleton.elim x default]
 #align eq_const_of_unique eq_const_of_unique

448144f7

bump to nightly-2023-02-21-16

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

1107b979

Changes in mathlib4

mathlib3

mathlib4

c4658a64

chore(Logic): reduce use of autoImplicit (#12135)

In one case, replacing this naively errored, so I just merged the single declaration using it.

Delete two unused variables in Logic/Basic.

f2658009

Diff

@@ -42,8 +42,6 @@ for good definitional properties of the default term.
 
 -/
 
-set_option autoImplicit true
-
 universe u v w
 
 /-- `Unique α` expresses that `α` is a type with a unique term `default`.
@@ -115,7 +113,7 @@ open Function
 
 section
 
-variable [Unique α]
+variable {α : Sort*} [Unique α]
 
 -- see Note [lower instance priority]
 instance (priority := 100) : Inhabited α :=
@@ -143,6 +141,8 @@ theorem exists_iff {p : α → Prop} : Exists p ↔ p default :=
 
 end
 
+variable {α : Sort*}
+
 @[ext]
 protected theorem subsingleton_unique' : ∀ h₁ h₂ : Unique α, h₁ = h₂
   | ⟨⟨x⟩, h⟩, ⟨⟨y⟩, _⟩ => by congr; rw [h x, h y]
@@ -166,6 +166,8 @@ theorem unique_iff_subsingleton_and_nonempty (α : Sort u) :
    fun ⟨hs, hn⟩ ↦ ⟨by inhabit α; exact Unique.mk' α⟩⟩
 #align unique_iff_subsingleton_and_nonempty unique_iff_subsingleton_and_nonempty
 
+variable {α : Sort*}
+
 @[simp]
 theorem Pi.default_def {β : α → Sort v} [∀ a, Inhabited (β a)] :
     @default (∀ a, β a) _ = fun a : α ↦ @default (β a) _ :=
@@ -185,11 +187,11 @@ instance Pi.uniqueOfIsEmpty [IsEmpty α] (β : α → Sort v) : Unique (∀ a, 
   default := isEmptyElim
   uniq _ := funext isEmptyElim
 
-theorem eq_const_of_subsingleton [Subsingleton α] (f : α → β) (a : α) :
+theorem eq_const_of_subsingleton {β : Sort*} [Subsingleton α] (f : α → β) (a : α) :
     f = Function.const α (f a) :=
   funext fun x ↦ Subsingleton.elim x a ▸ rfl
 
-theorem eq_const_of_unique [Unique α] (f : α → β) : f = Function.const α (f default) :=
+theorem eq_const_of_unique {β : Sort*} [Unique α] (f : α → β) : f = Function.const α (f default) :=
   eq_const_of_subsingleton ..
 #align eq_const_of_unique eq_const_of_unique
 
@@ -200,7 +202,7 @@ theorem heq_const_of_unique [Unique α] {β : α → Sort v} (f : ∀ a, β a) :
 
 namespace Function
 
-variable {f : α → β}
+variable {β : Sort*} {f : α → β}
 
 /-- If the codomain of an injective function is a subsingleton, then the domain
 is a subsingleton as well. -/
@@ -216,7 +218,8 @@ protected theorem Surjective.subsingleton [Subsingleton α] (hf : Surjective f)
 
 /-- If the domain of a surjective function is a singleton,
 then the codomain is a singleton as well. -/
-protected def Surjective.unique (f : α → β) (hf : Surjective f) [Unique.{u} α] : Unique β :=
+protected def Surjective.unique {α : Sort u} (f : α → β) (hf : Surjective f) [Unique.{u} α] :
+    Unique β :=
   @Unique.mk' _ ⟨f default⟩ hf.subsingleton
 #align function.surjective.unique Function.Surjective.unique
 
@@ -236,6 +239,7 @@ end Function
 section Pi
 
 variable {ι : Sort*} {α : ι → Sort*}
+
 /-- Given one value over a unique, we get a dependent function. -/
 def uniqueElim [Unique ι] (x : α (default : ι)) (i : ι) : α i := by
   rw [Unique.eq_default i]
@@ -246,7 +250,8 @@ theorem uniqueElim_default {_ : Unique ι} (x : α (default : ι)) : uniqueElim
   rfl
 
 @[simp]
-theorem uniqueElim_const {_ : Unique ι} (x : β) (i : ι) : uniqueElim (α := fun _ ↦ β) x i = x :=
+theorem uniqueElim_const {β : Sort*} {_ : Unique ι} (x : β) (i : ι) :
+    uniqueElim (α := fun _ ↦ β) x i = x :=
   rfl
 
 end Pi

c4658a64

refactor(Logic/Unique): remove dependency on Fin (#8510)

Unique should be available earlier than results about Fin n, by virtue of being a very basic logic typeclass with no dependencies on Nat or algebra.

This also generalizes some of the moved instances and lemmas. There are no new declarations in this PR, only renames of existing ones.

8b144faa

Diff

@@ -5,7 +5,6 @@ Authors: Johan Commelin
 -/
 import Mathlib.Logic.IsEmpty
 import Mathlib.Init.Logic
-import Mathlib.Init.Data.Fin.Basic
 import Mathlib.Tactic.Inhabit
 
 #align_import logic.unique from "leanprover-community/mathlib"@"c4658a649d216f57e99621708b09dcb3dcccbd23"
@@ -110,24 +109,6 @@ def uniqueProp {p : Prop} (h : p) : Unique.{0} p where
 instance : Unique True :=
   uniqueProp trivial
 
-theorem Fin.eq_zero : ∀ n : Fin 1, n = 0
-  | ⟨_, hn⟩ => Fin.eq_of_veq (Nat.eq_zero_of_le_zero (Nat.le_of_lt_succ hn))
-#align fin.eq_zero Fin.eq_zero
-
-instance {n : ℕ} : Inhabited (Fin n.succ) :=
-  ⟨0⟩
-
-instance inhabitedFinOneAdd (n : ℕ) : Inhabited (Fin (1 + n)) :=
-  ⟨⟨0, by rw [Nat.add_comm]; exact Nat.zero_lt_succ _⟩⟩
-
-@[simp]
-theorem Fin.default_eq_zero (n : ℕ) : (default : Fin n.succ) = 0 :=
-  rfl
-#align fin.default_eq_zero Fin.default_eq_zero
-
-instance Fin.unique : Unique (Fin 1) where
-  uniq := Fin.eq_zero
-
 namespace Unique
 
 open Function

c4658a64

fix: attribute [simp] ... in -> attribute [local simp] ... in (#7678)

Mathlib.Logic.Unique contains the line attribute [simp] eq_iff_true_of_subsingleton in ...:

https://github.com/leanprover-community/mathlib4/blob/96a11c7aac574c00370c2b3dab483cb676405c5d/Mathlib/Logic/Unique.lean#L255-L256

Despite what the in part may imply, this adds the lemma to the simp set "globally", including for downstream files; it is likely that attribute [local simp] eq_iff_true_of_subsingleton in ... was meant instead (or maybe scoped simp, but I think "scoped" refers to the current namespace). Indeed, the relevant lemma is not marked with @[simp] for possible slowness: https://github.com/leanprover/std4/blob/846e9e1d6bb534774d1acd2dc430e70987da3c18/Std/Logic.lean#L749. Adding it to the simp set causes the example at https://leanprover.zulipchat.com/#narrow/stream/287929-mathlib4/topic/Regression.20in.20simp to slow down.

This PR changes this and fixes the relevant downstream simps. There was also one ocurrence of attribute [simp] FullSubcategory.comp_def FullSubcategory.id_def in in Mathlib.CategoryTheory.Monoidal.Subcategory but that was much easier to fix.

https://github.com/leanprover-community/mathlib4/blob/bc49eb9ba756a233370b4b68bcdedd60402f71ed/Mathlib/CategoryTheory/Monoidal/Subcategory.lean#L118-L119

1fe87718

Diff

@@ -271,7 +271,7 @@ theorem uniqueElim_const {_ : Unique ι} (x : β) (i : ι) : uniqueElim (α := f
 end Pi
 
 -- TODO: Mario turned this off as a simp lemma in Std, wanting to profile it.
-attribute [simp] eq_iff_true_of_subsingleton in
+attribute [local simp] eq_iff_true_of_subsingleton in
 theorem Unique.bijective {A B} [Unique A] [Unique B] {f : A → B} : Function.Bijective f := by
   rw [Function.bijective_iff_has_inverse]
   refine' ⟨default, _, _⟩ <;> intro x <;> simp

c4658a64

feat: measurability of uniqueElim and piFinsetUnion (#8249)

The extra import doesn't add any additional imports transitively
Also use implicit arguments for some MeasurableSpace arguments for consistency with other lemmas.
Redefine Equiv.piSubsingleton and MulEquiv.piSubsingleton to Equiv.piUnique and MulEquiv.piUnique.

76efc30c

Diff

@@ -254,7 +254,7 @@ end Function
 
 section Pi
 
-variable {ι : Type*} {α : ι → Type*}
+variable {ι : Sort*} {α : ι → Sort*}
 /-- Given one value over a unique, we get a dependent function. -/
 def uniqueElim [Unique ι] (x : α (default : ι)) (i : ι) : α i := by
   rw [Unique.eq_default i]
@@ -264,6 +264,10 @@ def uniqueElim [Unique ι] (x : α (default : ι)) (i : ι) : α i := by
 theorem uniqueElim_default {_ : Unique ι} (x : α (default : ι)) : uniqueElim x (default : ι) = x :=
   rfl
 
+@[simp]
+theorem uniqueElim_const {_ : Unique ι} (x : β) (i : ι) : uniqueElim (α := fun _ ↦ β) x i = x :=
+  rfl
+
 end Pi
 
 -- TODO: Mario turned this off as a simp lemma in Std, wanting to profile it.

c4658a64

feat: define updateFinset which updates a finite number components of a vector (#7341)

from the Sobolev project (formerly: marginal project)

Co-authored-by: Mario Carneiro <di.gama@gmail.com>

0eb6b931

Diff

@@ -252,6 +252,20 @@ def Surjective.uniqueOfSurjectiveConst (α : Type*) {β : Type*} (b : β)
 
 end Function
 
+section Pi
+
+variable {ι : Type*} {α : ι → Type*}
+/-- Given one value over a unique, we get a dependent function. -/
+def uniqueElim [Unique ι] (x : α (default : ι)) (i : ι) : α i := by
+  rw [Unique.eq_default i]
+  exact x
+
+@[simp]
+theorem uniqueElim_default {_ : Unique ι} (x : α (default : ι)) : uniqueElim x (default : ι) = x :=
+  rfl
+
+end Pi
+
 -- TODO: Mario turned this off as a simp lemma in Std, wanting to profile it.
 attribute [simp] eq_iff_true_of_subsingleton in
 theorem Unique.bijective {A B} [Unique A] [Unique B] {f : A → B} : Function.Bijective f := by

c4658a64

feat: add Function.update_eq_const and eq_const_of_subsingleton (#7275)

Also golf Function.update_apply.

96a11c7a

Diff

@@ -204,10 +204,12 @@ instance Pi.uniqueOfIsEmpty [IsEmpty α] (β : α → Sort v) : Unique (∀ a, 
   default := isEmptyElim
   uniq _ := funext isEmptyElim
 
-theorem eq_const_of_unique [Unique α] (f : α → β) : f = Function.const α (f default) := by
-  ext x
-  rw [Subsingleton.elim x default]
-  rfl
+theorem eq_const_of_subsingleton [Subsingleton α] (f : α → β) (a : α) :
+    f = Function.const α (f a) :=
+  funext fun x ↦ Subsingleton.elim x a ▸ rfl
+
+theorem eq_const_of_unique [Unique α] (f : α → β) : f = Function.const α (f default) :=
+  eq_const_of_subsingleton ..
 #align eq_const_of_unique eq_const_of_unique
 
 theorem heq_const_of_unique [Unique α] {β : α → Sort v} (f : ∀ a, β a) :

c4658a64

chore: delay import of Tactic.Common (#7000)

I know that this is contrary to what we've done previously, but:

I'm trying to upstream a great many tactics from Mathlib to Std (essentially, everything that non-mathematicians want too).
This makes it much easier for me to see what is going on, and understand the import requirements (particularly for the "big" tactics norm_num / ring / linarith)
It's actually not as bad as it looks here, because as these tactics move up to Std they will start disappearing again from explicit imports, but Mathlib can happily import all of Std.

(Oh

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

4f3418a7

Diff

@@ -6,7 +6,7 @@ Authors: Johan Commelin
 import Mathlib.Logic.IsEmpty
 import Mathlib.Init.Logic
 import Mathlib.Init.Data.Fin.Basic
-import Mathlib.Tactic.Common
+import Mathlib.Tactic.Inhabit
 
 #align_import logic.unique from "leanprover-community/mathlib"@"c4658a649d216f57e99621708b09dcb3dcccbd23"

c4658a64

fix: disable autoImplicit globally (#6528)

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

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

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

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

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

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

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

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

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

0c24f831

Diff

@@ -43,6 +43,7 @@ for good definitional properties of the default term.
 
 -/
 
+set_option autoImplicit true
 
 universe u v w

c4658a64

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

@@ -82,7 +82,7 @@ equivalent by `Unique.Subsingleton.unique`.
 
 See note [reducible non-instances]. -/
 @[reducible]
-def uniqueOfSubsingleton {α : Sort _} [Subsingleton α] (a : α) : Unique α where
+def uniqueOfSubsingleton {α : Sort*} [Subsingleton α] (a : α) : Unique α where
   default := a
   uniq _ := Subsingleton.elim _ _
 #align unique_of_subsingleton uniqueOfSubsingleton
@@ -242,7 +242,7 @@ protected def Injective.unique [Inhabited α] [Subsingleton β] (hf : Injective
 #align function.injective.unique Function.Injective.unique
 
 /-- If a constant function is surjective, then the codomain is a singleton. -/
-def Surjective.uniqueOfSurjectiveConst (α : Type _) {β : Type _} (b : β)
+def Surjective.uniqueOfSurjectiveConst (α : Type*) {β : Type*} (b : β)
     (h : Function.Surjective (Function.const α b)) : Unique β :=
   @uniqueOfSubsingleton _ (subsingleton_of_forall_eq b <| h.forall.mpr fun _ ↦ rfl) b
 #align function.surjective.unique_of_surjective_const Function.Surjective.uniqueOfSurjectiveConst

c4658a64

chore: ensure all instances referred to directly have explicit names (#6423)

Per https://github.com/leanprover/lean4/issues/2343, we are going to need to change the automatic generation of instance names, as they become too long.

This PR ensures that everywhere in Mathlib that refers to an instance by name, that name is given explicitly, rather than being automatically generated.

There are four exceptions, which are now commented, with links to https://github.com/leanprover/lean4/issues/2343.

This was implemented by running Mathlib against a modified Lean that appended _ᾰ to all automatically generated names, and fixing everything.

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

65a35f78

Diff

@@ -148,7 +148,7 @@ theorem default_eq (a : α) : default = a :=
 #align unique.default_eq Unique.default_eq
 
 -- see Note [lower instance priority]
-instance (priority := 100) : Subsingleton α :=
+instance (priority := 100) instSubsingleton : Subsingleton α :=
   subsingleton_of_forall_eq _ eq_default
 
 theorem forall_iff {p : α → Prop} : (∀ a, p a) ↔ p default :=

c4658a64

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

@@ -2,17 +2,14 @@
 Copyright (c) 2019 Johan Commelin. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Johan Commelin
-
-! This file was ported from Lean 3 source module logic.unique
-! leanprover-community/mathlib commit c4658a649d216f57e99621708b09dcb3dcccbd23
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathlib.Logic.IsEmpty
 import Mathlib.Init.Logic
 import Mathlib.Init.Data.Fin.Basic
 import Mathlib.Tactic.Common
 
+#align_import logic.unique from "leanprover-community/mathlib"@"c4658a649d216f57e99621708b09dcb3dcccbd23"
+
 /-!
 # Types with a unique term

c4658a64

chore: fix upper/lowercase in comments (#4360)

Run a non-interactive version of fix-comments.py on all files.
Go through the diff and manually add/discard/edit chunks.

27d257fc

Diff

@@ -30,7 +30,7 @@ In other words, a type that is `Inhabited` and a `Subsingleton`.
   would lead to loops in typeclass inference.
 
 * `Function.Surjective.unique`: if the domain of a surjective function is `Unique`, then its
-  codomain is `unique` as well.
+  codomain is `Unique` as well.
 
 * `Function.Injective.subsingleton`: if the codomain of an injective function is `Subsingleton`,
   then its domain is `Subsingleton` as well.

c4658a64

feat: add Mathlib.Tactic.Common, and import (#4056)

This makes a mathlib4 version of mathlib3's tactic.basic, now called Mathlib.Tactic.Common, which imports all tactics which do not have significant theory requirements, and then is imported all across the base of the hierarchy.

This ensures that all common tactics are available nearly everywhere in the library, rather than having to be imported one-by-one as you need them.

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

a4eaf1c4

Diff

@@ -11,7 +11,7 @@ Authors: Johan Commelin
 import Mathlib.Logic.IsEmpty
 import Mathlib.Init.Logic
 import Mathlib.Init.Data.Fin.Basic
-import Mathlib.Tactic.Inhabit
+import Mathlib.Tactic.Common
 
 /-!
 # Types with a unique term

c4658a64

Revert "feat: add Mathlib.Tactic.Common, and import"

This reverts commit 1ce2f69b.

7a81a20c

Diff

@@ -11,7 +11,7 @@ Authors: Johan Commelin
 import Mathlib.Logic.IsEmpty
 import Mathlib.Init.Logic
 import Mathlib.Init.Data.Fin.Basic
-import Mathlib.Tactic.Common
+import Mathlib.Tactic.Inhabit
 
 /-!
 # Types with a unique term

c4658a64

feat: add Mathlib.Tactic.Common, and import

1ce2f69b

Diff

@@ -11,7 +11,7 @@ Authors: Johan Commelin
 import Mathlib.Logic.IsEmpty
 import Mathlib.Init.Logic
 import Mathlib.Init.Data.Fin.Basic
-import Mathlib.Tactic.Inhabit
+import Mathlib.Tactic.Common
 
 /-!
 # Types with a unique term

c4658a64

chore: fix #align lines (#3640)

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.)

2b42dc7c

Diff

@@ -101,7 +101,6 @@ instance PUnit.unique : Unique PUnit.{u} where
 @[simp, nolint simpNF]
 theorem PUnit.default_eq_unit : (default : PUnit) = PUnit.unit :=
   rfl
-
 #align punit.default_eq_star PUnit.default_eq_unit
 
 /-- Every provable proposition is unique, as all proofs are equal. -/

c4658a64

chore: add missing #align statements (#1902)

This PR is the result of a slight variant on the following "algorithm"

take all mathlib 3 names, remove _ and make all uppercase letters into lowercase
take all mathlib 4 names, remove _ and make all uppercase letters into lowercase
look for matches, and create pairs (original_lean3_name, OriginalLean4Name)
for pairs that do not have an align statement:
- use Lean 4 to lookup the file + position of the Lean 4 name
- add an #align statement just before the next empty line
manually fix some tiny mistakes (e.g., empty lines in proofs might cause the #align statement to have been inserted too early)

b72bb858

Diff

@@ -57,6 +57,9 @@ for good definitional properties of the default term. -/
 structure Unique (α : Sort u) extends Inhabited α where
   /-- In a `Unique` type, every term is equal to the default element (from `Inhabited`). -/
   uniq : ∀ a : α, a = default
+#align unique Unique
+#align unique.ext_iff Unique.ext_iff
+#align unique.ext Unique.ext
 
 attribute [class] Unique
 -- The simplifier can already prove this using `eq_iff_true_of_subsingleton`
@@ -65,6 +68,7 @@ attribute [nolint simpNF] Unique.mk.injEq
 theorem unique_iff_exists_unique (α : Sort u) : Nonempty (Unique α) ↔ ∃! _ : α, True :=
   ⟨fun ⟨u⟩ ↦ ⟨u.default, trivial, fun a _ ↦ u.uniq a⟩,
    fun ⟨a, _, h⟩ ↦ ⟨⟨⟨a⟩, fun _ ↦ h _ trivial⟩⟩⟩
+#align unique_iff_exists_unique unique_iff_exists_unique
 
 theorem unique_subtype_iff_exists_unique {α} (p : α → Prop) :
     Nonempty (Unique (Subtype p)) ↔ ∃! a, p a :=
@@ -72,6 +76,7 @@ theorem unique_subtype_iff_exists_unique {α} (p : α → Prop) :
    fun ⟨a, ha, he⟩ ↦ ⟨⟨⟨⟨a, ha⟩⟩, fun ⟨b, hb⟩ ↦ by
       congr
       exact he b hb⟩⟩⟩
+#align unique_subtype_iff_exists_unique unique_subtype_iff_exists_unique
 
 /-- Given an explicit `a : α` with `Subsingleton α`, we can construct
 a `Unique α` instance. This is a def because the typeclass search cannot
@@ -83,6 +88,7 @@ See note [reducible non-instances]. -/
 def uniqueOfSubsingleton {α : Sort _} [Subsingleton α] (a : α) : Unique α where
   default := a
   uniq _ := Subsingleton.elim _ _
+#align unique_of_subsingleton uniqueOfSubsingleton
 
 instance PUnit.unique : Unique PUnit.{u} where
   default := PUnit.unit
@@ -102,12 +108,14 @@ theorem PUnit.default_eq_unit : (default : PUnit) = PUnit.unit :=
 def uniqueProp {p : Prop} (h : p) : Unique.{0} p where
   default := h
   uniq _ := rfl
+#align unique_prop uniqueProp
 
 instance : Unique True :=
   uniqueProp trivial
 
 theorem Fin.eq_zero : ∀ n : Fin 1, n = 0
   | ⟨_, hn⟩ => Fin.eq_of_veq (Nat.eq_zero_of_le_zero (Nat.le_of_lt_succ hn))
+#align fin.eq_zero Fin.eq_zero
 
 instance {n : ℕ} : Inhabited (Fin n.succ) :=
   ⟨0⟩
@@ -118,6 +126,7 @@ instance inhabitedFinOneAdd (n : ℕ) : Inhabited (Fin (1 + n)) :=
 @[simp]
 theorem Fin.default_eq_zero (n : ℕ) : (default : Fin n.succ) = 0 :=
   rfl
+#align fin.default_eq_zero Fin.default_eq_zero
 
 instance Fin.unique : Unique (Fin 1) where
   uniq := Fin.eq_zero
@@ -136,9 +145,11 @@ instance (priority := 100) : Inhabited α :=
 
 theorem eq_default (a : α) : a = default :=
   uniq _ a
+#align unique.eq_default Unique.eq_default
 
 theorem default_eq (a : α) : default = a :=
   (uniq _ a).symm
+#align unique.default_eq Unique.default_eq
 
 -- see Note [lower instance priority]
 instance (priority := 100) : Subsingleton α :=
@@ -146,15 +157,18 @@ instance (priority := 100) : Subsingleton α :=
 
 theorem forall_iff {p : α → Prop} : (∀ a, p a) ↔ p default :=
   ⟨fun h ↦ h _, fun h x ↦ by rwa [Unique.eq_default x]⟩
+#align unique.forall_iff Unique.forall_iff
 
 theorem exists_iff {p : α → Prop} : Exists p ↔ p default :=
   ⟨fun ⟨a, ha⟩ ↦ eq_default a ▸ ha, Exists.intro default⟩
+#align unique.exists_iff Unique.exists_iff
 
 end
 
 @[ext]
 protected theorem subsingleton_unique' : ∀ h₁ h₂ : Unique α, h₁ = h₂
   | ⟨⟨x⟩, h⟩, ⟨⟨y⟩, _⟩ => by congr; rw [h x, h y]
+#align unique.subsingleton_unique' Unique.subsingleton_unique'
 
 instance subsingleton_unique : Subsingleton (Unique α) :=
   ⟨Unique.subsingleton_unique'⟩
@@ -164,6 +178,7 @@ a loop in the class inheritance graph. -/
 @[reducible]
 def mk' (α : Sort u) [h₁ : Inhabited α] [Subsingleton α] : Unique α :=
   { h₁ with uniq := fun _ ↦ Subsingleton.elim _ _ }
+#align unique.mk' Unique.mk'
 
 end Unique
 
@@ -171,15 +186,18 @@ theorem unique_iff_subsingleton_and_nonempty (α : Sort u) :
     Nonempty (Unique α) ↔ Subsingleton α ∧ Nonempty α :=
   ⟨fun ⟨u⟩ ↦ by constructor <;> exact inferInstance,
    fun ⟨hs, hn⟩ ↦ ⟨by inhabit α; exact Unique.mk' α⟩⟩
+#align unique_iff_subsingleton_and_nonempty unique_iff_subsingleton_and_nonempty
 
 @[simp]
 theorem Pi.default_def {β : α → Sort v} [∀ a, Inhabited (β a)] :
     @default (∀ a, β a) _ = fun a : α ↦ @default (β a) _ :=
   rfl
+#align pi.default_def Pi.default_def
 
 theorem Pi.default_apply {β : α → Sort v} [∀ a, Inhabited (β a)] (a : α) :
     @default (∀ a, β a) _ a = default :=
   rfl
+#align pi.default_apply Pi.default_apply
 
 instance Pi.unique {β : α → Sort v} [∀ a, Unique (β a)] : Unique (∀ a, β a) where
   uniq := fun _ ↦ funext fun _ ↦ Unique.eq_default _
@@ -193,10 +211,12 @@ theorem eq_const_of_unique [Unique α] (f : α → β) : f = Function.const α (
   ext x
   rw [Subsingleton.elim x default]
   rfl
+#align eq_const_of_unique eq_const_of_unique
 
 theorem heq_const_of_unique [Unique α] {β : α → Sort v} (f : ∀ a, β a) :
     HEq f (Function.const α (f default)) :=
   (Function.hfunext rfl) fun i _ _ ↦ by rw [Subsingleton.elim i default]; rfl
+#align heq_const_of_unique heq_const_of_unique
 
 namespace Function
 
@@ -206,25 +226,30 @@ variable {f : α → β}
 is a subsingleton as well. -/
 protected theorem Injective.subsingleton (hf : Injective f) [Subsingleton β] : Subsingleton α :=
   ⟨fun _ _ ↦ hf <| Subsingleton.elim _ _⟩
+#align function.injective.subsingleton Function.Injective.subsingleton
 
 /-- If the domain of a surjective function is a subsingleton, then the codomain is a subsingleton as
 well. -/
 protected theorem Surjective.subsingleton [Subsingleton α] (hf : Surjective f) : Subsingleton β :=
   ⟨hf.forall₂.2 fun x y ↦ congr_arg f <| Subsingleton.elim x y⟩
+#align function.surjective.subsingleton Function.Surjective.subsingleton
 
 /-- If the domain of a surjective function is a singleton,
 then the codomain is a singleton as well. -/
 protected def Surjective.unique (f : α → β) (hf : Surjective f) [Unique.{u} α] : Unique β :=
   @Unique.mk' _ ⟨f default⟩ hf.subsingleton
+#align function.surjective.unique Function.Surjective.unique
 
 /-- If `α` is inhabited and admits an injective map to a subsingleton type, then `α` is `Unique`. -/
 protected def Injective.unique [Inhabited α] [Subsingleton β] (hf : Injective f) : Unique α :=
   @Unique.mk' _ _ hf.subsingleton
+#align function.injective.unique Function.Injective.unique
 
 /-- If a constant function is surjective, then the codomain is a singleton. -/
 def Surjective.uniqueOfSurjectiveConst (α : Type _) {β : Type _} (b : β)
     (h : Function.Surjective (Function.const α b)) : Unique β :=
   @uniqueOfSubsingleton _ (subsingleton_of_forall_eq b <| h.forall.mpr fun _ ↦ rfl) b
+#align function.surjective.unique_of_surjective_const Function.Surjective.uniqueOfSurjectiveConst
 
 end Function
 
@@ -233,6 +258,7 @@ attribute [simp] eq_iff_true_of_subsingleton in
 theorem Unique.bijective {A B} [Unique A] [Unique B] {f : A → B} : Function.Bijective f := by
   rw [Function.bijective_iff_has_inverse]
   refine' ⟨default, _, _⟩ <;> intro x <;> simp
+#align unique.bijective Unique.bijective
 
 namespace Option

c4658a64

chore: fix casing per naming scheme (#1183)

Fix a lot of wrong casing mostly in the docstrings but also sometimes in def/theorem names. E.g. fin 2 --> Fin 2, add_monoid_hom --> AddMonoidHom

Remove \n from to_additive docstrings that were inserted by mathport.

Move files and directories with Gcd and Smul to GCD and SMul

71723d8b

Diff

@@ -236,7 +236,7 @@ theorem Unique.bijective {A B} [Unique A] [Unique B] {f : A → B} : Function.Bi
 
 namespace Option
 
-/-- `option α` is a `subsingleton` if and only if `α` is empty. -/
+/-- `Option α` is a `Subsingleton` if and only if `α` is empty. -/
 theorem subsingleton_iff_isEmpty {α : Type u} : Subsingleton (Option α) ↔ IsEmpty α :=
   ⟨fun h ↦ ⟨fun x ↦ Option.noConfusion <| @Subsingleton.elim _ h x none⟩,
    fun h ↦ ⟨fun x y ↦

c4658a64

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) 2019 Johan Commelin. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Johan Commelin
+
+! This file was ported from Lean 3 source module logic.unique
+! leanprover-community/mathlib commit c4658a649d216f57e99621708b09dcb3dcccbd23
+! Please do not edit these lines, except to modify the commit id
+! if you have ported upstream changes.
 -/
 import Mathlib.Logic.IsEmpty
 import Mathlib.Init.Logic

`logic.unique` ⟷ `Mathlib.Logic.Unique`

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 5

logic.unique ⟷ Mathlib.Logic.Unique

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 5

`logic.unique` ⟷ `Mathlib.Logic.Unique`