data.countable.basic | 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

1f0096e6

(last sync)

Changes in mathlib3port

mathlib3

mathlib3port

63f84d91

bump to nightly-2023-09-24-06

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

5655435f

Diff

@@ -3,9 +3,9 @@ Copyright (c) 2022 Yury Kudryashov. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Yury Kudryashov
 -/
-import Mathbin.Logic.Equiv.Nat
-import Mathbin.Logic.Equiv.Fin
-import Mathbin.Data.Countable.Defs
+import Logic.Equiv.Nat
+import Logic.Equiv.Fin
+import Data.Countable.Defs
 
 #align_import data.countable.basic from "leanprover-community/mathlib"@"63f84d91dd847f50bae04a01071f3a5491934e36"

63f84d91

bump to nightly-2023-07-20-09

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

9c56d0dd

Diff

@@ -2,16 +2,13 @@
 Copyright (c) 2022 Yury Kudryashov. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Yury Kudryashov
-
-! This file was ported from Lean 3 source module data.countable.basic
-! leanprover-community/mathlib commit 63f84d91dd847f50bae04a01071f3a5491934e36
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathbin.Logic.Equiv.Nat
 import Mathbin.Logic.Equiv.Fin
 import Mathbin.Data.Countable.Defs
 
+#align_import data.countable.basic from "leanprover-community/mathlib"@"63f84d91dd847f50bae04a01071f3a5491934e36"
+
 /-!
 # Countable types

63f84d91

bump to nightly-2023-06-01-16

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

b9c87c70

Diff

@@ -112,7 +112,7 @@ instance [Countable α] [Countable β] : Countable (PProd α β) :=
   Countable.of_equiv (PLift α × PLift β) (Equiv.plift.prodPProd Equiv.plift)
 
 instance [Countable α] [∀ a, Countable (π a)] : Countable (PSigma π) :=
-  Countable.of_equiv (Σa : PLift α, PLift (π a.down)) (Equiv.psigmaEquivSigmaPLift π).symm
+  Countable.of_equiv (Σ a : PLift α, PLift (π a.down)) (Equiv.psigmaEquivSigmaPLift π).symm
 
 instance [Finite α] [∀ a, Countable (π a)] : Countable (∀ a, π a) :=
   by

63f84d91

bump to nightly-2023-05-28-04

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

6797a637

Diff

@@ -117,8 +117,7 @@ instance [Countable α] [∀ a, Countable (π a)] : Countable (PSigma π) :=
 instance [Finite α] [∀ a, Countable (π a)] : Countable (∀ a, π a) :=
   by
   have : ∀ n, Countable (Fin n → ℕ) := by
-    intro n
-    induction' n with n ihn
+    intro n; induction' n with n ihn
     · infer_instance
     · exact Countable.of_equiv _ (Equiv.piFinSucc _ _).symm
   rcases Finite.exists_equiv_fin α with ⟨n, ⟨e⟩⟩

63f84d91

bump to nightly-2023-02-21-16

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

1107b979

Changes in mathlib4

mathlib3

mathlib4

1f0096e6

feat: Add Uncountable (#9254)

Adds the Uncountable class to Countable/Defs and some basic API.

Co-authored-by: Yury G. Kudryashov <urkud@urkud.name>

b50557ce

Diff

@@ -35,6 +35,9 @@ theorem countable_iff_nonempty_embedding : Countable α ↔ Nonempty (α ↪ ℕ
   ⟨fun ⟨⟨f, hf⟩⟩ => ⟨⟨f, hf⟩⟩, fun ⟨f⟩ => ⟨⟨f, f.2⟩⟩⟩
 #align countable_iff_nonempty_embedding countable_iff_nonempty_embedding
 
+theorem uncountable_iff_isEmpty_embedding : Uncountable α ↔ IsEmpty (α ↪ ℕ) := by
+  rw [← not_countable_iff, countable_iff_nonempty_embedding, not_nonempty_iff]
+
 theorem nonempty_embedding_nat (α) [Countable α] : Nonempty (α ↪ ℕ) :=
   countable_iff_nonempty_embedding.1 ‹_›
 #align nonempty_embedding_nat nonempty_embedding_nat
@@ -43,6 +46,9 @@ protected theorem Function.Embedding.countable [Countable β] (f : α ↪ β) :
   f.injective.countable
 #align function.embedding.countable Function.Embedding.countable
 
+protected lemma Function.Embedding.uncountable [Uncountable α] (f : α ↪ β) : Uncountable β :=
+  f.injective.uncountable
+
 end Embedding
 
 /-!
@@ -53,24 +59,51 @@ section type
 
 variable {α : Type u} {β : Type v} {π : α → Type w}
 
-instance [Countable α] [Countable β] : Countable (Sum α β) := by
+instance [Countable α] [Countable β] : Countable (α ⊕ β) := by
   rcases exists_injective_nat α with ⟨f, hf⟩
   rcases exists_injective_nat β with ⟨g, hg⟩
   exact (Equiv.natSumNatEquivNat.injective.comp <| hf.sum_map hg).countable
 
+instance Sum.uncountable_inl [Uncountable α] : Uncountable (α ⊕ β) :=
+  inl_injective.uncountable
+
+instance Sum.uncountable_inr [Uncountable β] : Uncountable (α ⊕ β) :=
+  inr_injective.uncountable
+
 instance [Countable α] : Countable (Option α) :=
   Countable.of_equiv _ (Equiv.optionEquivSumPUnit.{_, 0} α).symm
 
+instance Option.instUncountable [Uncountable α] : Uncountable (Option α) :=
+  Injective.uncountable fun _ _ ↦ Option.some_inj.1
+
 instance [Countable α] [Countable β] : Countable (α × β) := by
   rcases exists_injective_nat α with ⟨f, hf⟩
   rcases exists_injective_nat β with ⟨g, hg⟩
   exact (Nat.pairEquiv.injective.comp <| hf.Prod_map hg).countable
 
+instance [Uncountable α] [Nonempty β] : Uncountable (α × β) := by
+  inhabit β
+  exact (Prod.mk.inj_right default).uncountable
+
+instance [Nonempty α] [Uncountable β] : Uncountable (α × β) := by
+  inhabit α
+  exact (Prod.mk.inj_left default).uncountable
+
 instance [Countable α] [∀ a, Countable (π a)] : Countable (Sigma π) := by
   rcases exists_injective_nat α with ⟨f, hf⟩
   choose g hg using fun a => exists_injective_nat (π a)
   exact ((Equiv.sigmaEquivProd ℕ ℕ).injective.comp <| hf.sigma_map hg).countable
 
+lemma Sigma.uncountable (a : α) [Uncountable (π a)] : Uncountable (Sigma π) :=
+  (sigma_mk_injective (i := a)).uncountable
+
+instance [Nonempty α] [∀ a, Uncountable (π a)] : Uncountable (Sigma π) := by
+  inhabit α; exact Sigma.uncountable default
+
+instance (priority := 500) SetCoe.countable [Countable α] (s : Set α) : Countable s :=
+  Subtype.countable
+#align set_coe.countable SetCoe.countable
+
 end type
 
 section sort
@@ -81,12 +114,8 @@ variable {α : Sort u} {β : Sort v} {π : α → Sort w}
 ### Operations on `Sort*`s
 -/
 
-instance (priority := 500) SetCoe.countable {α} [Countable α] (s : Set α) : Countable s :=
-  Subtype.countable
-#align set_coe.countable SetCoe.countable
-
-instance [Countable α] [Countable β] : Countable (PSum α β) :=
-  Countable.of_equiv (Sum (PLift α) (PLift β)) (Equiv.plift.sumPSum Equiv.plift)
+instance [Countable α] [Countable β] : Countable (α ⊕' β) :=
+  Countable.of_equiv (PLift α ⊕ PLift β) (Equiv.plift.sumPSum Equiv.plift)
 
 instance [Countable α] [Countable β] : Countable (PProd α β) :=
   Countable.of_equiv (PLift α × PLift β) (Equiv.plift.prodPProd Equiv.plift)

1f0096e6

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

@@ -46,7 +46,7 @@ protected theorem Function.Embedding.countable [Countable β] (f : α ↪ β) :
 end Embedding
 
 /-!
-### Operations on `Type _`s
+### Operations on `Type*`s
 -/
 
 section type
@@ -78,7 +78,7 @@ section sort
 variable {α : Sort u} {β : Sort v} {π : α → Sort w}
 
 /-!
-### Operations on `Sort _`s
+### Operations on `Sort*`s
 -/
 
 instance (priority := 500) SetCoe.countable {α} [Countable α] (s : Set α) : Countable s :=

1f0096e6

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

@@ -2,16 +2,13 @@
 Copyright (c) 2022 Yury Kudryashov. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Yury Kudryashov
-
-! This file was ported from Lean 3 source module data.countable.basic
-! leanprover-community/mathlib commit 1f0096e6caa61e9c849ec2adbd227e960e9dff58
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathlib.Logic.Equiv.Nat
 import Mathlib.Logic.Equiv.Fin
 import Mathlib.Data.Countable.Defs
 
+#align_import data.countable.basic from "leanprover-community/mathlib"@"1f0096e6caa61e9c849ec2adbd227e960e9dff58"
+
 /-!
 # Countable types

1f0096e6

chore: rename mkpair → pair (#2324)

We rename the ported mkpair to pair, as mkpair didn't follow the naming convention and pair pairs well with unpair. A poll for this decision was held on zulip.

869fc2fd

Diff

@@ -67,7 +67,7 @@ instance [Countable α] : Countable (Option α) :=
 instance [Countable α] [Countable β] : Countable (α × β) := by
   rcases exists_injective_nat α with ⟨f, hf⟩
   rcases exists_injective_nat β with ⟨g, hg⟩
-  exact (Nat.mkpairEquiv.injective.comp <| hf.Prod_map hg).countable
+  exact (Nat.pairEquiv.injective.comp <| hf.Prod_map hg).countable
 
 instance [Countable α] [∀ a, Countable (π a)] : Countable (Sigma π) := by
   rcases exists_injective_nat α with ⟨f, hf⟩
@@ -109,4 +109,3 @@ instance [Finite α] [∀ a, Countable (π a)] : Countable (∀ a, π a) := by
   exact ((Embedding.piCongrRight f).trans (Equiv.piCongrLeft' _ e).toEmbedding).countable
 
 end sort
-

1f0096e6

Feat: port Data.Countable.Basic (#1787)

Co-authored-by: Johan Commelin <johan@commelin.net>

09d11b47

`data.countable.basic` ⟷ `Mathlib.Data.Countable.Basic`

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 2 + 160

data.countable.basic ⟷ Mathlib.Data.Countable.Basic

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 2 + 160

`data.countable.basic` ⟷ `Mathlib.Data.Countable.Basic`