logic.is_empty | 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-2023-10-21-06

mathlib commit https://github.com/leanprover-community/mathlib/commit/b1abe23ae96fef89ad30d9f4362c307f72a55010

a2dc86f8

Diff

@@ -194,7 +194,7 @@ theorem isEmpty_Prop {p : Prop} : IsEmpty p ↔ ¬p := by simp only [← not_non
 #print isEmpty_pi /-
 @[simp]
 theorem isEmpty_pi {π : α → Sort _} : IsEmpty (∀ a, π a) ↔ ∃ a, IsEmpty (π a) := by
-  simp only [← not_nonempty_iff, Classical.nonempty_pi, not_forall]
+  simp only [← not_nonempty_iff, Classical.nonempty_pi, Classical.not_forall]
 #align is_empty_pi isEmpty_pi
 -/

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) 2021 Floris van Doorn. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Floris van Doorn
 -/
-import Mathbin.Logic.Function.Basic
-import Mathbin.Tactic.Protected
+import Logic.Function.Basic
+import Tactic.Protected
 
 #align_import logic.is_empty 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) 2021 Floris van Doorn. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Floris van Doorn
-
-! This file was ported from Lean 3 source module logic.is_empty
-! 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.Logic.Function.Basic
 import Mathbin.Tactic.Protected
 
+#align_import logic.is_empty from "leanprover-community/mathlib"@"448144f7ae193a8990cb7473c9e9a01990f64ac7"
+
 /-!
 # Types that are empty

448144f7

bump to nightly-2023-06-13-21

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

829520ac

Diff

@@ -201,15 +201,19 @@ theorem isEmpty_pi {π : α → Sort _} : IsEmpty (∀ a, π a) ↔ ∃ a, IsEmp
 #align is_empty_pi isEmpty_pi
 -/
 
+#print isEmpty_sigma /-
 @[simp]
 theorem isEmpty_sigma {α} {E : α → Type _} : IsEmpty (Sigma E) ↔ ∀ a, IsEmpty (E a) := by
   simp only [← not_nonempty_iff, nonempty_sigma, not_exists]
 #align is_empty_sigma isEmpty_sigma
+-/
 
+#print isEmpty_psigma /-
 @[simp]
 theorem isEmpty_psigma {α} {E : α → Sort _} : IsEmpty (PSigma E) ↔ ∀ a, IsEmpty (E a) := by
   simp only [← not_nonempty_iff, nonempty_psigma, not_exists]
 #align is_empty_psigma isEmpty_psigma
+-/
 
 #print isEmpty_subtype /-
 @[simp]
@@ -218,10 +222,12 @@ theorem isEmpty_subtype (p : α → Prop) : IsEmpty (Subtype p) ↔ ∀ x, ¬p x
 #align is_empty_subtype isEmpty_subtype
 -/
 
+#print isEmpty_prod /-
 @[simp]
 theorem isEmpty_prod {α β : Type _} : IsEmpty (α × β) ↔ IsEmpty α ∨ IsEmpty β := by
   simp only [← not_nonempty_iff, nonempty_prod, not_and_or]
 #align is_empty_prod isEmpty_prod
+-/
 
 #print isEmpty_pprod /-
 @[simp]
@@ -230,20 +236,26 @@ theorem isEmpty_pprod : IsEmpty (PProd α β) ↔ IsEmpty α ∨ IsEmpty β := b
 #align is_empty_pprod isEmpty_pprod
 -/
 
+#print isEmpty_sum /-
 @[simp]
 theorem isEmpty_sum {α β} : IsEmpty (Sum α β) ↔ IsEmpty α ∧ IsEmpty β := by
   simp only [← not_nonempty_iff, nonempty_sum, not_or]
 #align is_empty_sum isEmpty_sum
+-/
 
+#print isEmpty_psum /-
 @[simp]
 theorem isEmpty_psum {α β} : IsEmpty (PSum α β) ↔ IsEmpty α ∧ IsEmpty β := by
   simp only [← not_nonempty_iff, nonempty_psum, not_or]
 #align is_empty_psum isEmpty_psum
+-/
 
+#print isEmpty_ulift /-
 @[simp]
 theorem isEmpty_ulift {α} : IsEmpty (ULift α) ↔ IsEmpty α := by
   simp only [← not_nonempty_iff, nonempty_ulift]
 #align is_empty_ulift isEmpty_ulift
+-/
 
 #print isEmpty_plift /-
 @[simp]
@@ -275,8 +287,10 @@ theorem not_isEmpty_of_nonempty [h : Nonempty α] : ¬IsEmpty α :=
 
 variable {α}
 
+#print Function.extend_of_isEmpty /-
 theorem Function.extend_of_isEmpty [IsEmpty α] (f : α → β) (g : α → γ) (h : β → γ) :
     Function.extend f g h = h :=
   funext fun x => Function.extend_apply' _ _ _ fun ⟨a, h⟩ => isEmptyElim a
 #align function.extend_of_empty Function.extend_of_isEmpty
+-/

448144f7

bump to nightly-2023-05-28-06

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

ba5d8b97

Diff

@@ -201,23 +201,11 @@ theorem isEmpty_pi {π : α → Sort _} : IsEmpty (∀ a, π a) ↔ ∃ a, IsEmp
 #align is_empty_pi isEmpty_pi
 -/
 
-/- warning: is_empty_sigma -> isEmpty_sigma is a dubious translation:
-lean 3 declaration is
-  forall {α : Type.{u1}} {E : α -> Type.{u2}}, Iff (IsEmpty.{max (succ u1) (succ u2)} (Sigma.{u1, u2} α E)) (forall (a : α), IsEmpty.{succ u2} (E a))
-but is expected to have type
-  forall {α : Type.{u2}} {E : α -> Type.{u1}}, Iff (IsEmpty.{max (succ u1) (succ u2)} (Sigma.{u2, u1} α E)) (forall (a : α), IsEmpty.{succ u1} (E a))
-Case conversion may be inaccurate. Consider using '#align is_empty_sigma isEmpty_sigmaₓ'. -/
 @[simp]
 theorem isEmpty_sigma {α} {E : α → Type _} : IsEmpty (Sigma E) ↔ ∀ a, IsEmpty (E a) := by
   simp only [← not_nonempty_iff, nonempty_sigma, not_exists]
 #align is_empty_sigma isEmpty_sigma
 
-/- warning: is_empty_psigma -> isEmpty_psigma is a dubious translation:
-lean 3 declaration is
-  forall {α : Sort.{u1}} {E : α -> Sort.{u2}}, Iff (IsEmpty.{max 1 u1 u2} (PSigma.{u1, u2} α E)) (forall (a : α), IsEmpty.{u2} (E a))
-but is expected to have type
-  forall {α : Sort.{u2}} {E : α -> Sort.{u1}}, Iff (IsEmpty.{max (max 1 u1) u2} (PSigma.{u2, u1} α E)) (forall (a : α), IsEmpty.{u1} (E a))
-Case conversion may be inaccurate. Consider using '#align is_empty_psigma isEmpty_psigmaₓ'. -/
 @[simp]
 theorem isEmpty_psigma {α} {E : α → Sort _} : IsEmpty (PSigma E) ↔ ∀ a, IsEmpty (E a) := by
   simp only [← not_nonempty_iff, nonempty_psigma, not_exists]
@@ -230,12 +218,6 @@ theorem isEmpty_subtype (p : α → Prop) : IsEmpty (Subtype p) ↔ ∀ x, ¬p x
 #align is_empty_subtype isEmpty_subtype
 -/
 
-/- warning: is_empty_prod -> isEmpty_prod is a dubious translation:
-lean 3 declaration is
-  forall {α : Type.{u1}} {β : Type.{u2}}, Iff (IsEmpty.{max (succ u1) (succ u2)} (Prod.{u1, u2} α β)) (Or (IsEmpty.{succ u1} α) (IsEmpty.{succ u2} β))
-but is expected to have type
-  forall {α : Type.{u2}} {β : Type.{u1}}, Iff (IsEmpty.{max (succ u1) (succ u2)} (Prod.{u2, u1} α β)) (Or (IsEmpty.{succ u2} α) (IsEmpty.{succ u1} β))
-Case conversion may be inaccurate. Consider using '#align is_empty_prod isEmpty_prodₓ'. -/
 @[simp]
 theorem isEmpty_prod {α β : Type _} : IsEmpty (α × β) ↔ IsEmpty α ∨ IsEmpty β := by
   simp only [← not_nonempty_iff, nonempty_prod, not_and_or]
@@ -248,34 +230,16 @@ theorem isEmpty_pprod : IsEmpty (PProd α β) ↔ IsEmpty α ∨ IsEmpty β := b
 #align is_empty_pprod isEmpty_pprod
 -/
 
-/- warning: is_empty_sum -> isEmpty_sum is a dubious translation:
-lean 3 declaration is
-  forall {α : Type.{u1}} {β : Type.{u2}}, Iff (IsEmpty.{max (succ u1) (succ u2)} (Sum.{u1, u2} α β)) (And (IsEmpty.{succ u1} α) (IsEmpty.{succ u2} β))
-but is expected to have type
-  forall {α : Type.{u2}} {β : Type.{u1}}, Iff (IsEmpty.{max (succ u1) (succ u2)} (Sum.{u2, u1} α β)) (And (IsEmpty.{succ u2} α) (IsEmpty.{succ u1} β))
-Case conversion may be inaccurate. Consider using '#align is_empty_sum isEmpty_sumₓ'. -/
 @[simp]
 theorem isEmpty_sum {α β} : IsEmpty (Sum α β) ↔ IsEmpty α ∧ IsEmpty β := by
   simp only [← not_nonempty_iff, nonempty_sum, not_or]
 #align is_empty_sum isEmpty_sum
 
-/- warning: is_empty_psum -> isEmpty_psum is a dubious translation:
-lean 3 declaration is
-  forall {α : Sort.{u1}} {β : Sort.{u2}}, Iff (IsEmpty.{max 1 u1 u2} (PSum.{u1, u2} α β)) (And (IsEmpty.{u1} α) (IsEmpty.{u2} β))
-but is expected to have type
-  forall {α : Sort.{u2}} {β : Sort.{u1}}, Iff (IsEmpty.{max (max 1 u1) u2} (PSum.{u2, u1} α β)) (And (IsEmpty.{u2} α) (IsEmpty.{u1} β))
-Case conversion may be inaccurate. Consider using '#align is_empty_psum isEmpty_psumₓ'. -/
 @[simp]
 theorem isEmpty_psum {α β} : IsEmpty (PSum α β) ↔ IsEmpty α ∧ IsEmpty β := by
   simp only [← not_nonempty_iff, nonempty_psum, not_or]
 #align is_empty_psum isEmpty_psum
 
-/- warning: is_empty_ulift -> isEmpty_ulift is a dubious translation:
-lean 3 declaration is
-  forall {α : Type.{u1}}, Iff (IsEmpty.{succ (max u1 u2)} (ULift.{u2, u1} α)) (IsEmpty.{succ u1} α)
-but is expected to have type
-  forall {α : Type.{u2}}, Iff (IsEmpty.{max (succ u2) (succ u1)} (ULift.{u1, u2} α)) (IsEmpty.{succ u2} α)
-Case conversion may be inaccurate. Consider using '#align is_empty_ulift isEmpty_uliftₓ'. -/
 @[simp]
 theorem isEmpty_ulift {α} : IsEmpty (ULift α) ↔ IsEmpty α := by
   simp only [← not_nonempty_iff, nonempty_ulift]
@@ -311,12 +275,6 @@ theorem not_isEmpty_of_nonempty [h : Nonempty α] : ¬IsEmpty α :=
 
 variable {α}
 
-/- warning: function.extend_of_empty -> Function.extend_of_isEmpty is a dubious translation:
-lean 3 declaration is
-  forall {α : Sort.{u1}} {β : Sort.{u2}} {γ : Sort.{u3}} [_inst_1 : IsEmpty.{u1} α] (f : α -> β) (g : α -> γ) (h : β -> γ), Eq.{imax u2 u3} (β -> γ) (Function.extend.{u1, u2, u3} α β γ f g h) h
-but is expected to have type
-  forall {α : Sort.{u3}} {β : Sort.{u2}} {γ : Sort.{u1}} [_inst_1 : IsEmpty.{u3} α] (f : α -> β) (g : α -> γ) (h : β -> γ), Eq.{imax u2 u1} (β -> γ) (Function.extend.{u3, u2, u1} α β γ f g h) h
-Case conversion may be inaccurate. Consider using '#align function.extend_of_empty Function.extend_of_isEmptyₓ'. -/
 theorem Function.extend_of_isEmpty [IsEmpty α] (f : α → β) (g : α → γ) (h : β → γ) :
     Function.extend f g h = h :=
   funext fun x => Function.extend_apply' _ _ _ fun ⟨a, h⟩ => isEmptyElim a

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

@@ -17,9 +17,6 @@ In this file we define a typeclass `IsEmpty`, which expresses that a type has no
 * `IsEmpty`: a typeclass that expresses that a type is empty.
 -/
 
-set_option autoImplicit true
-
-
 variable {α β γ : Sort*}
 
 /-- `IsEmpty α` expresses that `α` is empty. -/
@@ -108,6 +105,7 @@ namespace IsEmpty
 
 open Function
 
+universe u in
 /-- Eliminate out of a type that `IsEmpty` (using projection notation). -/
 @[elab_as_elim]
 protected def elim {α : Sort u} (_ : IsEmpty α) {p : α → Sort*} (a : α) : p a :=

c4658a64

feat(Logic/IsEmpty): add instances for Quot and Quotient (#11616)

f4fd1b19

Diff

@@ -46,6 +46,9 @@ protected theorem Function.isEmpty [IsEmpty β] (f : α → β) : IsEmpty α :=
   ⟨fun x ↦ IsEmpty.false (f x)⟩
 #align function.is_empty Function.isEmpty
 
+theorem Function.Surjective.isEmpty [IsEmpty α] {f : α → β} (hf : f.Surjective) : IsEmpty β :=
+  ⟨fun y ↦ let ⟨x, _⟩ := hf y; IsEmpty.false x⟩
+
 instance {p : α → Sort*} [h : Nonempty α] [∀ x, IsEmpty (p x)] : IsEmpty (∀ x, p x) :=
   h.elim fun x ↦ Function.isEmpty <| Function.eval x
 
@@ -61,6 +64,12 @@ instance Prod.isEmpty_left {α β} [IsEmpty α] : IsEmpty (α × β) :=
 instance Prod.isEmpty_right {α β} [IsEmpty β] : IsEmpty (α × β) :=
   Function.isEmpty Prod.snd
 
+instance Quot.instIsEmpty {α : Sort*} [IsEmpty α] {r : α → α → Prop} : IsEmpty (Quot r) :=
+  Function.Surjective.isEmpty Quot.exists_rep
+
+instance Quotient.instIsEmpty {α : Sort*} [IsEmpty α] {s : Setoid α} : IsEmpty (Quotient s) :=
+  Quot.instIsEmpty
+
 instance [IsEmpty α] [IsEmpty β] : IsEmpty (PSum α β) :=
   ⟨fun x ↦ PSum.rec IsEmpty.false IsEmpty.false x⟩

c4658a64

feat(Cardinal): #(α ≃ β) and #(α ↪ β) in the infinite case (#9646)

Main results:

If two types have the same infinite cardinality, then there are as many Equivs between them as there are functions.
If B has infinite cardinality no less than #A, then there are as many embeddings from A into B as there are functions.
If A has infinite cardinality no less than #B, then there are as many surjective functions from A to B as there are functions.

Co-authored-by: Junyan Xu <junyanxu.math@gmail.com>

d91d6797

Diff

@@ -153,6 +153,14 @@ theorem isEmpty_pi {π : α → Sort*} : IsEmpty (∀ a, π a) ↔ ∃ a, IsEmpt
   simp only [← not_nonempty_iff, Classical.nonempty_pi, not_forall]
 #align is_empty_pi isEmpty_pi
 
+@[simp]
+theorem isEmpty_fun : IsEmpty (α → β) ↔ Nonempty α ∧ IsEmpty β := by
+  rw [isEmpty_pi, ← exists_true_iff_nonempty, ← exists_and_right, true_and]
+
+@[simp]
+theorem nonempty_fun : Nonempty (α → β) ↔ IsEmpty α ∨ Nonempty β :=
+  not_iff_not.mp <| by rw [not_or, not_nonempty_iff, not_nonempty_iff, isEmpty_fun, not_isEmpty_iff]
+
 @[simp]
 theorem isEmpty_sigma {α} {E : α → Type*} : IsEmpty (Sigma E) ↔ ∀ a, IsEmpty (E a) := by
   simp only [← not_nonempty_iff, nonempty_sigma, not_exists]

c4658a64

chore: tidy various files (#7009)

23ffa510

Diff

@@ -39,6 +39,9 @@ instance : IsEmpty False :=
 instance Fin.isEmpty : IsEmpty (Fin 0) :=
   ⟨fun n ↦ Nat.not_lt_zero n.1 n.2⟩
 
+instance Fin.isEmpty' : IsEmpty (Fin Nat.zero) :=
+  Fin.isEmpty
+
 protected theorem Function.isEmpty [IsEmpty β] (f : α → β) : IsEmpty α :=
   ⟨fun x ↦ IsEmpty.false (f x)⟩
 #align function.is_empty Function.isEmpty

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

@@ -17,6 +17,8 @@ In this file we define a typeclass `IsEmpty`, which expresses that a type has no
 * `IsEmpty`: a typeclass that expresses that a type is empty.
 -/
 
+set_option autoImplicit true
+
 
 variable {α β γ : Sort*}

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

@@ -18,10 +18,10 @@ In this file we define a typeclass `IsEmpty`, which expresses that a type has no
 -/
 
 
-variable {α β γ : Sort _}
+variable {α β γ : Sort*}
 
 /-- `IsEmpty α` expresses that `α` is empty. -/
-class IsEmpty (α : Sort _) : Prop where
+class IsEmpty (α : Sort*) : Prop where
   protected false : α → False
 #align is_empty IsEmpty
 
@@ -41,7 +41,7 @@ protected theorem Function.isEmpty [IsEmpty β] (f : α → β) : IsEmpty α :=
   ⟨fun x ↦ IsEmpty.false (f x)⟩
 #align function.is_empty Function.isEmpty
 
-instance {p : α → Sort _} [h : Nonempty α] [∀ x, IsEmpty (p x)] : IsEmpty (∀ x, p x) :=
+instance {p : α → Sort*} [h : Nonempty α] [∀ x, IsEmpty (p x)] : IsEmpty (∀ x, p x) :=
   h.elim fun x ↦ Function.isEmpty <| Function.eval x
 
 instance PProd.isEmpty_left [IsEmpty α] : IsEmpty (PProd α β) :=
@@ -75,14 +75,14 @@ theorem Subtype.isEmpty_of_false {p : α → Prop} (hp : ∀ a, ¬p a) : IsEmpty
 instance Subtype.isEmpty_false : IsEmpty { _a : α // False } :=
   Subtype.isEmpty_of_false fun _ ↦ id
 
-instance Sigma.isEmpty_left {α} [IsEmpty α] {E : α → Type _} : IsEmpty (Sigma E) :=
+instance Sigma.isEmpty_left {α} [IsEmpty α] {E : α → Type*} : IsEmpty (Sigma E) :=
   Function.isEmpty Sigma.fst
 
 example [h : Nonempty α] [IsEmpty β] : IsEmpty (α → β) := by infer_instance
 
 /-- Eliminate out of a type that `IsEmpty` (without using projection notation). -/
 @[elab_as_elim]
-def isEmptyElim [IsEmpty α] {p : α → Sort _} (a : α) : p a :=
+def isEmptyElim [IsEmpty α] {p : α → Sort*} (a : α) : p a :=
   (IsEmpty.false a).elim
 #align is_empty_elim isEmptyElim
 
@@ -96,13 +96,13 @@ open Function
 
 /-- Eliminate out of a type that `IsEmpty` (using projection notation). -/
 @[elab_as_elim]
-protected def elim {α : Sort u} (_ : IsEmpty α) {p : α → Sort _} (a : α) : p a :=
+protected def elim {α : Sort u} (_ : IsEmpty α) {p : α → Sort*} (a : α) : p a :=
   isEmptyElim a
 #align is_empty.elim IsEmpty.elim
 
 /-- Non-dependent version of `IsEmpty.elim`. Helpful if the elaborator cannot elaborate `h.elim a`
   correctly. -/
-protected def elim' {β : Sort _} (h : IsEmpty α) (a : α) : β :=
+protected def elim' {β : Sort*} (h : IsEmpty α) (a : α) : β :=
   (h.false a).elim
 #align is_empty.elim' IsEmpty.elim'
 
@@ -144,17 +144,17 @@ theorem isEmpty_Prop {p : Prop} : IsEmpty p ↔ ¬p := by
 #align is_empty_Prop isEmpty_Prop
 
 @[simp]
-theorem isEmpty_pi {π : α → Sort _} : IsEmpty (∀ a, π a) ↔ ∃ a, IsEmpty (π a) := by
+theorem isEmpty_pi {π : α → Sort*} : IsEmpty (∀ a, π a) ↔ ∃ a, IsEmpty (π a) := by
   simp only [← not_nonempty_iff, Classical.nonempty_pi, not_forall]
 #align is_empty_pi isEmpty_pi
 
 @[simp]
-theorem isEmpty_sigma {α} {E : α → Type _} : IsEmpty (Sigma E) ↔ ∀ a, IsEmpty (E a) := by
+theorem isEmpty_sigma {α} {E : α → Type*} : IsEmpty (Sigma E) ↔ ∀ a, IsEmpty (E a) := by
   simp only [← not_nonempty_iff, nonempty_sigma, not_exists]
 #align is_empty_sigma isEmpty_sigma
 
 @[simp]
-theorem isEmpty_psigma {α} {E : α → Sort _} : IsEmpty (PSigma E) ↔ ∀ a, IsEmpty (E a) := by
+theorem isEmpty_psigma {α} {E : α → Sort*} : IsEmpty (PSigma E) ↔ ∀ a, IsEmpty (E a) := by
   simp only [← not_nonempty_iff, nonempty_psigma, not_exists]
 #align is_empty_psigma isEmpty_psigma
 
@@ -164,7 +164,7 @@ theorem isEmpty_subtype (p : α → Prop) : IsEmpty (Subtype p) ↔ ∀ x, ¬p x
 #align is_empty_subtype isEmpty_subtype
 
 @[simp]
-theorem isEmpty_prod {α β : Type _} : IsEmpty (α × β) ↔ IsEmpty α ∨ IsEmpty β := by
+theorem isEmpty_prod {α β : Type*} : IsEmpty (α × β) ↔ IsEmpty α ∨ IsEmpty β := by
   simp only [← not_nonempty_iff, nonempty_prod, not_and_or]
 #align is_empty_prod isEmpty_prod

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

@@ -25,10 +25,10 @@ class IsEmpty (α : Sort _) : Prop where
   protected false : α → False
 #align is_empty IsEmpty
 
-instance : IsEmpty Empty :=
+instance instIsEmptyEmpty : IsEmpty Empty :=
   ⟨Empty.elim⟩
 
-instance : IsEmpty PEmpty :=
+instance instIsEmptyPEmpty : IsEmpty PEmpty :=
   ⟨PEmpty.elim⟩
 
 instance : IsEmpty False :=
@@ -59,7 +59,7 @@ instance Prod.isEmpty_right {α β} [IsEmpty β] : IsEmpty (α × β) :=
 instance [IsEmpty α] [IsEmpty β] : IsEmpty (PSum α β) :=
   ⟨fun x ↦ PSum.rec IsEmpty.false IsEmpty.false x⟩
 
-instance {α β} [IsEmpty α] [IsEmpty β] : IsEmpty (Sum α β) :=
+instance instIsEmptySum {α β} [IsEmpty α] [IsEmpty β] : IsEmpty (Sum α β) :=
   ⟨fun x ↦ Sum.rec IsEmpty.false IsEmpty.false x⟩
 
 /-- subtypes of an empty type are empty -/

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

@@ -2,14 +2,11 @@
 Copyright (c) 2021 Floris van Doorn. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Floris van Doorn
-
-! This file was ported from Lean 3 source module logic.is_empty
-! 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.Function.Basic
 
+#align_import logic.is_empty from "leanprover-community/mathlib"@"c4658a649d216f57e99621708b09dcb3dcccbd23"
+
 /-!
 # Types that are empty

c4658a64

feat: port RingTheory.PowerBasis (#4238)

e1328b4a

Diff

@@ -37,7 +37,7 @@ instance : IsEmpty PEmpty :=
 instance : IsEmpty False :=
   ⟨id⟩
 
-instance : IsEmpty (Fin 0) :=
+instance Fin.isEmpty : IsEmpty (Fin 0) :=
   ⟨fun n ↦ Nat.not_lt_zero n.1 n.2⟩
 
 protected theorem Function.isEmpty [IsEmpty β] (f : α → β) : IsEmpty α :=

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

@@ -26,6 +26,7 @@ variable {α β γ : Sort _}
 /-- `IsEmpty α` expresses that `α` is empty. -/
 class IsEmpty (α : Sort _) : Prop where
   protected false : α → False
+#align is_empty IsEmpty
 
 instance : IsEmpty Empty :=
   ⟨Empty.elim⟩
@@ -86,6 +87,7 @@ example [h : Nonempty α] [IsEmpty β] : IsEmpty (α → β) := by infer_instanc
 @[elab_as_elim]
 def isEmptyElim [IsEmpty α] {p : α → Sort _} (a : α) : p a :=
   (IsEmpty.false a).elim
+#align is_empty_elim isEmptyElim
 
 theorem isEmpty_iff : IsEmpty α ↔ α → False :=
   ⟨@IsEmpty.false α, IsEmpty.mk⟩
@@ -99,24 +101,29 @@ open Function
 @[elab_as_elim]
 protected def elim {α : Sort u} (_ : IsEmpty α) {p : α → Sort _} (a : α) : p a :=
   isEmptyElim a
+#align is_empty.elim IsEmpty.elim
 
 /-- Non-dependent version of `IsEmpty.elim`. Helpful if the elaborator cannot elaborate `h.elim a`
   correctly. -/
 protected def elim' {β : Sort _} (h : IsEmpty α) (a : α) : β :=
   (h.false a).elim
+#align is_empty.elim' IsEmpty.elim'
 
 protected theorem prop_iff {p : Prop} : IsEmpty p ↔ ¬p :=
   isEmpty_iff
+#align is_empty.prop_iff IsEmpty.prop_iff
 
 variable [IsEmpty α]
 
 @[simp]
 theorem forall_iff {p : α → Prop} : (∀ a, p a) ↔ True :=
   iff_true_intro isEmptyElim
+#align is_empty.forall_iff IsEmpty.forall_iff
 
 @[simp]
 theorem exists_iff {p : α → Prop} : (∃ a, p a) ↔ False :=
   iff_false_intro fun ⟨x, _⟩ ↦ IsEmpty.false x
+#align is_empty.exists_iff IsEmpty.exists_iff
 
 -- see Note [lower instance priority]
 instance (priority := 100) : Subsingleton α :=
@@ -127,6 +134,7 @@ end IsEmpty
 @[simp]
 theorem not_nonempty_iff : ¬Nonempty α ↔ IsEmpty α :=
   ⟨fun h ↦ ⟨fun x ↦ h ⟨x⟩⟩, fun h1 h2 ↦ h2.elim h1.elim⟩
+#align not_nonempty_iff not_nonempty_iff
 
 @[simp]
 theorem not_isEmpty_iff : ¬IsEmpty α ↔ Nonempty α :=

c4658a64

chore: remove iff_self from simp only after lean4#1933 (#1406)

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

72b23bd4

Diff

@@ -135,57 +135,57 @@ theorem not_isEmpty_iff : ¬IsEmpty α ↔ Nonempty α :=
 
 @[simp]
 theorem isEmpty_Prop {p : Prop} : IsEmpty p ↔ ¬p := by
-  simp only [← not_nonempty_iff, nonempty_Prop, iff_self]
+  simp only [← not_nonempty_iff, nonempty_Prop]
 #align is_empty_Prop isEmpty_Prop
 
 @[simp]
 theorem isEmpty_pi {π : α → Sort _} : IsEmpty (∀ a, π a) ↔ ∃ a, IsEmpty (π a) := by
-  simp only [← not_nonempty_iff, Classical.nonempty_pi, not_forall, iff_self]
+  simp only [← not_nonempty_iff, Classical.nonempty_pi, not_forall]
 #align is_empty_pi isEmpty_pi
 
 @[simp]
 theorem isEmpty_sigma {α} {E : α → Type _} : IsEmpty (Sigma E) ↔ ∀ a, IsEmpty (E a) := by
-  simp only [← not_nonempty_iff, nonempty_sigma, not_exists, iff_self]
+  simp only [← not_nonempty_iff, nonempty_sigma, not_exists]
 #align is_empty_sigma isEmpty_sigma
 
 @[simp]
 theorem isEmpty_psigma {α} {E : α → Sort _} : IsEmpty (PSigma E) ↔ ∀ a, IsEmpty (E a) := by
-  simp only [← not_nonempty_iff, nonempty_psigma, not_exists, iff_self]
+  simp only [← not_nonempty_iff, nonempty_psigma, not_exists]
 #align is_empty_psigma isEmpty_psigma
 
 @[simp]
 theorem isEmpty_subtype (p : α → Prop) : IsEmpty (Subtype p) ↔ ∀ x, ¬p x := by
-  simp only [← not_nonempty_iff, nonempty_subtype, not_exists, iff_self]
+  simp only [← not_nonempty_iff, nonempty_subtype, not_exists]
 #align is_empty_subtype isEmpty_subtype
 
 @[simp]
 theorem isEmpty_prod {α β : Type _} : IsEmpty (α × β) ↔ IsEmpty α ∨ IsEmpty β := by
-  simp only [← not_nonempty_iff, nonempty_prod, not_and_or, iff_self]
+  simp only [← not_nonempty_iff, nonempty_prod, not_and_or]
 #align is_empty_prod isEmpty_prod
 
 @[simp]
 theorem isEmpty_pprod : IsEmpty (PProd α β) ↔ IsEmpty α ∨ IsEmpty β := by
-  simp only [← not_nonempty_iff, nonempty_pprod, not_and_or, iff_self]
+  simp only [← not_nonempty_iff, nonempty_pprod, not_and_or]
 #align is_empty_pprod isEmpty_pprod
 
 @[simp]
 theorem isEmpty_sum {α β} : IsEmpty (Sum α β) ↔ IsEmpty α ∧ IsEmpty β := by
-  simp only [← not_nonempty_iff, nonempty_sum, not_or, iff_self]
+  simp only [← not_nonempty_iff, nonempty_sum, not_or]
 #align is_empty_sum isEmpty_sum
 
 @[simp]
 theorem isEmpty_psum {α β} : IsEmpty (PSum α β) ↔ IsEmpty α ∧ IsEmpty β := by
-  simp only [← not_nonempty_iff, nonempty_psum, not_or, iff_self]
+  simp only [← not_nonempty_iff, nonempty_psum, not_or]
 #align is_empty_psum isEmpty_psum
 
 @[simp]
 theorem isEmpty_ulift {α} : IsEmpty (ULift α) ↔ IsEmpty α := by
-  simp only [← not_nonempty_iff, nonempty_ulift, iff_self]
+  simp only [← not_nonempty_iff, nonempty_ulift]
 #align is_empty_ulift isEmpty_ulift
 
 @[simp]
 theorem isEmpty_plift {α} : IsEmpty (PLift α) ↔ IsEmpty α := by
-  simp only [← not_nonempty_iff, nonempty_plift, iff_self]
+  simp only [← not_nonempty_iff, nonempty_plift]
 #align is_empty_plift isEmpty_plift
 
 theorem wellFounded_of_isEmpty {α} [IsEmpty α] (r : α → α → Prop) : WellFounded r :=

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) 2021 Floris van Doorn. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Floris van Doorn
+
+! This file was ported from Lean 3 source module logic.is_empty
+! 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.Function.Basic

`logic.is_empty` ⟷ `Mathlib.Logic.IsEmpty`

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 4

logic.is_empty ⟷ Mathlib.Logic.IsEmpty

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 4

`logic.is_empty` ⟷ `Mathlib.Logic.IsEmpty`