data.fintype.powerset | 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

509de852

(last sync)

Changes in mathlib3port

mathlib3

mathlib3port

327c3c0d

bump to nightly-2024-02-01-06

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

5433bded

Diff

@@ -72,7 +72,12 @@ theorem Fintype.card_finset_len [Fintype α] (k : ℕ) :
 
 #print Set.fintype /-
 instance Set.fintype [Fintype α] : Fintype (Set α) :=
-  ⟨(@Finset.univ α _).powerset.map ⟨coe, coe_injective⟩, fun s => by classical⟩
+  ⟨(@Finset.univ α _).powerset.map ⟨coe, coe_injective⟩, fun s => by
+    classical
+    refine' mem_map.2 ⟨finset.univ.filter s, mem_powerset.2 (subset_univ _), _⟩
+    apply (coe_filter _ _).trans
+    rw [coe_univ, Set.sep_univ]
+    rfl⟩
 #align set.fintype Set.fintype
 -/

327c3c0d

bump to nightly-2024-01-31-06

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

61100fe9

Diff

@@ -72,12 +72,7 @@ theorem Fintype.card_finset_len [Fintype α] (k : ℕ) :
 
 #print Set.fintype /-
 instance Set.fintype [Fintype α] : Fintype (Set α) :=
-  ⟨(@Finset.univ α _).powerset.map ⟨coe, coe_injective⟩, fun s => by
-    classical
-    refine' mem_map.2 ⟨finset.univ.filter s, mem_powerset.2 (subset_univ _), _⟩
-    apply (coe_filter _ _).trans
-    rw [coe_univ, Set.sep_univ]
-    rfl⟩
+  ⟨(@Finset.univ α _).powerset.map ⟨coe, coe_injective⟩, fun s => by classical⟩
 #align set.fintype Set.fintype
 -/

327c3c0d

bump to nightly-2023-10-19-06

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

3af48615

Diff

@@ -47,18 +47,18 @@ theorem Finset.powerset_eq_univ [Fintype α] {s : Finset α} : s.powerset = univ
 #align finset.powerset_eq_univ Finset.powerset_eq_univ
 -/
 
-#print Finset.mem_powersetLen_univ /-
-theorem Finset.mem_powersetLen_univ [Fintype α] {s : Finset α} {k : ℕ} :
-    s ∈ powersetLen k (univ : Finset α) ↔ card s = k :=
-  mem_powersetLen.trans <| and_iff_right <| subset_univ _
-#align finset.mem_powerset_len_univ_iff Finset.mem_powersetLen_univ
+#print Finset.mem_powersetCard_univ /-
+theorem Finset.mem_powersetCard_univ [Fintype α] {s : Finset α} {k : ℕ} :
+    s ∈ powersetCard k (univ : Finset α) ↔ card s = k :=
+  mem_powersetCard.trans <| and_iff_right <| subset_univ _
+#align finset.mem_powerset_len_univ_iff Finset.mem_powersetCard_univ
 -/
 
 #print Finset.univ_filter_card_eq /-
 @[simp]
 theorem Finset.univ_filter_card_eq (α : Type _) [Fintype α] (k : ℕ) :
-    ((Finset.univ : Finset (Finset α)).filterₓ fun s => s.card = k) = Finset.univ.powersetLen k :=
-  by ext; simp [Finset.mem_powersetLen]
+    ((Finset.univ : Finset (Finset α)).filterₓ fun s => s.card = k) = Finset.univ.powersetCard k :=
+  by ext; simp [Finset.mem_powersetCard]
 #align finset.univ_filter_card_eq Finset.univ_filter_card_eq
 -/

327c3c0d

bump to nightly-2023-09-30-06

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

0742bc05

Diff

@@ -47,11 +47,11 @@ theorem Finset.powerset_eq_univ [Fintype α] {s : Finset α} : s.powerset = univ
 #align finset.powerset_eq_univ Finset.powerset_eq_univ
 -/
 
-#print Finset.mem_powerset_len_univ_iff /-
-theorem Finset.mem_powerset_len_univ_iff [Fintype α] {s : Finset α} {k : ℕ} :
+#print Finset.mem_powersetLen_univ /-
+theorem Finset.mem_powersetLen_univ [Fintype α] {s : Finset α} {k : ℕ} :
     s ∈ powersetLen k (univ : Finset α) ↔ card s = k :=
   mem_powersetLen.trans <| and_iff_right <| subset_univ _
-#align finset.mem_powerset_len_univ_iff Finset.mem_powerset_len_univ_iff
+#align finset.mem_powerset_len_univ_iff Finset.mem_powersetLen_univ
 -/
 
 #print Finset.univ_filter_card_eq /-

327c3c0d

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) 2017 Mario Carneiro. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Mario Carneiro
 -/
-import Mathbin.Data.Fintype.Card
-import Mathbin.Data.Finset.Powerset
+import Data.Fintype.Card
+import Data.Finset.Powerset
 
 #align_import data.fintype.powerset from "leanprover-community/mathlib"@"327c3c0d9232d80e250dc8f65e7835b82b266ea5"

327c3c0d

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) 2017 Mario Carneiro. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Mario Carneiro
-
-! This file was ported from Lean 3 source module data.fintype.powerset
-! leanprover-community/mathlib commit 327c3c0d9232d80e250dc8f65e7835b82b266ea5
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathbin.Data.Fintype.Card
 import Mathbin.Data.Finset.Powerset
 
+#align_import data.fintype.powerset from "leanprover-community/mathlib"@"327c3c0d9232d80e250dc8f65e7835b82b266ea5"
+
 /-!
 # fintype instance for `set α`, when `α` is a fintype

327c3c0d

bump to nightly-2023-06-13-21

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

829520ac

Diff

@@ -57,17 +57,21 @@ theorem Finset.mem_powerset_len_univ_iff [Fintype α] {s : Finset α} {k : ℕ}
 #align finset.mem_powerset_len_univ_iff Finset.mem_powerset_len_univ_iff
 -/
 
+#print Finset.univ_filter_card_eq /-
 @[simp]
 theorem Finset.univ_filter_card_eq (α : Type _) [Fintype α] (k : ℕ) :
     ((Finset.univ : Finset (Finset α)).filterₓ fun s => s.card = k) = Finset.univ.powersetLen k :=
   by ext; simp [Finset.mem_powersetLen]
 #align finset.univ_filter_card_eq Finset.univ_filter_card_eq
+-/
 
+#print Fintype.card_finset_len /-
 @[simp]
 theorem Fintype.card_finset_len [Fintype α] (k : ℕ) :
     Fintype.card { s : Finset α // s.card = k } = Nat.choose (Fintype.card α) k := by
   simp [Fintype.subtype_card, Finset.card_univ]
 #align fintype.card_finset_len Fintype.card_finset_len
+-/
 
 #print Set.fintype /-
 instance Set.fintype [Fintype α] : Fintype (Set α) :=

327c3c0d

bump to nightly-2023-06-04-18

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

3fb4268b

Diff

@@ -73,10 +73,10 @@ theorem Fintype.card_finset_len [Fintype α] (k : ℕ) :
 instance Set.fintype [Fintype α] : Fintype (Set α) :=
   ⟨(@Finset.univ α _).powerset.map ⟨coe, coe_injective⟩, fun s => by
     classical
-      refine' mem_map.2 ⟨finset.univ.filter s, mem_powerset.2 (subset_univ _), _⟩
-      apply (coe_filter _ _).trans
-      rw [coe_univ, Set.sep_univ]
-      rfl⟩
+    refine' mem_map.2 ⟨finset.univ.filter s, mem_powerset.2 (subset_univ _), _⟩
+    apply (coe_filter _ _).trans
+    rw [coe_univ, Set.sep_univ]
+    rfl⟩
 #align set.fintype Set.fintype
 -/

327c3c0d

bump to nightly-2023-05-28-06

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

ba5d8b97

Diff

@@ -57,24 +57,12 @@ theorem Finset.mem_powerset_len_univ_iff [Fintype α] {s : Finset α} {k : ℕ}
 #align finset.mem_powerset_len_univ_iff Finset.mem_powerset_len_univ_iff
 -/
 
-/- warning: finset.univ_filter_card_eq -> Finset.univ_filter_card_eq is a dubious translation:
-lean 3 declaration is
-  forall (α : Type.{u1}) [_inst_1 : Fintype.{u1} α] (k : Nat), Eq.{succ u1} (Finset.{u1} (Finset.{u1} α)) (Finset.filter.{u1} (Finset.{u1} α) (fun (s : Finset.{u1} α) => Eq.{1} Nat (Finset.card.{u1} α s) k) (fun (a : Finset.{u1} α) => Nat.decidableEq (Finset.card.{u1} α a) k) (Finset.univ.{u1} (Finset.{u1} α) (Finset.fintype.{u1} α _inst_1))) (Finset.powersetLen.{u1} α k (Finset.univ.{u1} α _inst_1))
-but is expected to have type
-  forall (α : Type.{u1}) [_inst_1 : Fintype.{u1} α] (k : Nat), Eq.{succ u1} (Finset.{u1} (Finset.{u1} α)) (Finset.filter.{u1} (Finset.{u1} α) (fun (s : Finset.{u1} α) => Eq.{1} Nat (Finset.card.{u1} α s) k) (fun (a : Finset.{u1} α) => instDecidableEqNat (Finset.card.{u1} α a) k) (Finset.univ.{u1} (Finset.{u1} α) (Finset.fintype.{u1} α _inst_1))) (Finset.powersetLen.{u1} α k (Finset.univ.{u1} α _inst_1))
-Case conversion may be inaccurate. Consider using '#align finset.univ_filter_card_eq Finset.univ_filter_card_eqₓ'. -/
 @[simp]
 theorem Finset.univ_filter_card_eq (α : Type _) [Fintype α] (k : ℕ) :
     ((Finset.univ : Finset (Finset α)).filterₓ fun s => s.card = k) = Finset.univ.powersetLen k :=
   by ext; simp [Finset.mem_powersetLen]
 #align finset.univ_filter_card_eq Finset.univ_filter_card_eq
 
-/- warning: fintype.card_finset_len -> Fintype.card_finset_len is a dubious translation:
-lean 3 declaration is
-  forall {α : Type.{u1}} [_inst_1 : Fintype.{u1} α] (k : Nat), Eq.{1} Nat (Fintype.card.{u1} (Subtype.{succ u1} (Finset.{u1} α) (fun (s : Finset.{u1} α) => Eq.{1} Nat (Finset.card.{u1} α s) k)) (Subtype.fintype.{u1} (Finset.{u1} α) (fun (s : Finset.{u1} α) => Eq.{1} Nat (Finset.card.{u1} α s) k) (fun (a : Finset.{u1} α) => Nat.decidableEq (Finset.card.{u1} α a) k) (Finset.fintype.{u1} α _inst_1))) (Nat.choose (Fintype.card.{u1} α _inst_1) k)
-but is expected to have type
-  forall {α : Type.{u1}} [_inst_1 : Fintype.{u1} α] (k : Nat), Eq.{1} Nat (Fintype.card.{u1} (Subtype.{succ u1} (Finset.{u1} α) (fun (s : Finset.{u1} α) => Eq.{1} Nat (Finset.card.{u1} α s) k)) (Subtype.fintype.{u1} (Finset.{u1} α) (fun (s : Finset.{u1} α) => Eq.{1} Nat (Finset.card.{u1} α s) k) (fun (a : Finset.{u1} α) => instDecidableEqNat (Finset.card.{u1} α a) k) (Finset.fintype.{u1} α _inst_1))) (Nat.choose (Fintype.card.{u1} α _inst_1) k)
-Case conversion may be inaccurate. Consider using '#align fintype.card_finset_len Fintype.card_finset_lenₓ'. -/
 @[simp]
 theorem Fintype.card_finset_len [Fintype α] (k : ℕ) :
     Fintype.card { s : Finset α // s.card = k } = Nat.choose (Fintype.card α) k := by

327c3c0d

bump to nightly-2023-05-28-04

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

6797a637

Diff

@@ -66,9 +66,7 @@ Case conversion may be inaccurate. Consider using '#align finset.univ_filter_car
 @[simp]
 theorem Finset.univ_filter_card_eq (α : Type _) [Fintype α] (k : ℕ) :
     ((Finset.univ : Finset (Finset α)).filterₓ fun s => s.card = k) = Finset.univ.powersetLen k :=
-  by
-  ext
-  simp [Finset.mem_powersetLen]
+  by ext; simp [Finset.mem_powersetLen]
 #align finset.univ_filter_card_eq Finset.univ_filter_card_eq
 
 /- warning: fintype.card_finset_len -> Fintype.card_finset_len is a dubious translation:
@@ -96,10 +94,7 @@ instance Set.fintype [Fintype α] : Fintype (Set α) :=
 
 #print Set.finite' /-
 -- Not to be confused with `set.finite`, the predicate
-instance Set.finite' [Finite α] : Finite (Set α) :=
-  by
-  cases nonempty_fintype α
-  infer_instance
+instance Set.finite' [Finite α] : Finite (Set α) := by cases nonempty_fintype α; infer_instance
 #align set.finite' Set.finite'
 -/

327c3c0d

bump to nightly-2023-02-21-16

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

1107b979

Changes in mathlib4

mathlib3

mathlib4

509de852

chore(*Set): golf (#12117)

Golf Directed.exists_mem_subset_of_finset_subset_biUnion using induction tactic.
Golf Set.fintype.
Reduce abuse of Set α = α → Prop defeq.

02b6c2be

Diff

@@ -59,12 +59,10 @@ theorem Fintype.card_finset_len [Fintype α] (k : ℕ) :
 #align fintype.card_finset_len Fintype.card_finset_len
 
 instance Set.fintype [Fintype α] : Fintype (Set α) :=
-  ⟨(@Finset.univ α _).powerset.map ⟨(↑), coe_injective⟩, fun s => by
+  ⟨(@Finset.univ (Finset α) _).map coeEmb.1, fun s => by
     classical
-      refine' mem_map.2 ⟨Finset.univ.filter s, Finset.mem_powerset.2 (Finset.subset_univ _), _⟩
-      apply (coe_filter _ _).trans
-      simp
-      rfl⟩
+    refine mem_map.2 ⟨Finset.univ.filter (· ∈ s), Finset.mem_univ _, (coe_filter _ _).trans ?_⟩
+    simp⟩
 #align set.fintype Set.fintype
 
 -- Not to be confused with `Set.Finite`, the predicate

509de852

feat: Basic finset lemmas (#9530)

From LeanAPAP

7445e724

Diff

@@ -40,7 +40,7 @@ lemma filter_subset_univ [DecidableEq α] (s : Finset α) :
   rw [← Finset.powerset_univ, powerset_inj]
 #align finset.powerset_eq_univ Finset.powerset_eq_univ
 
-@[simp] lemma mem_powersetCard_univ : s ∈ powersetCard k (univ : Finset α) ↔ card s = k :=
+lemma mem_powersetCard_univ : s ∈ powersetCard k (univ : Finset α) ↔ card s = k :=
   mem_powersetCard.trans <| and_iff_right <| subset_univ _
 #align finset.mem_powerset_len_univ_iff Finset.mem_powersetCard_univ

509de852

chore: rename Finset.powersetLen to powersetCard (#7667)

I don't understand why this was ever named powersetLen, there isn't even the notion of the length of a Finset/Multiset.

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

75dfd25e

Diff

@@ -40,14 +40,14 @@ lemma filter_subset_univ [DecidableEq α] (s : Finset α) :
   rw [← Finset.powerset_univ, powerset_inj]
 #align finset.powerset_eq_univ Finset.powerset_eq_univ
 
-@[simp] lemma mem_powersetLen_univ : s ∈ powersetLen k (univ : Finset α) ↔ card s = k :=
-  mem_powersetLen.trans <| and_iff_right <| subset_univ _
-#align finset.mem_powerset_len_univ_iff Finset.mem_powersetLen_univ
+@[simp] lemma mem_powersetCard_univ : s ∈ powersetCard k (univ : Finset α) ↔ card s = k :=
+  mem_powersetCard.trans <| and_iff_right <| subset_univ _
+#align finset.mem_powerset_len_univ_iff Finset.mem_powersetCard_univ
 
 variable (α)
 
 @[simp] lemma univ_filter_card_eq (k : ℕ) :
-    (univ : Finset (Finset α)).filter (fun s ↦ s.card = k) = univ.powersetLen k := by ext; simp
+    (univ : Finset (Finset α)).filter (fun s ↦ s.card = k) = univ.powersetCard k := by ext; simp
 #align finset.univ_filter_card_eq Finset.univ_filter_card_eq
 
 end Finset

509de852

feat: Order isomorphism between Finset α and Set α (#7375)

over a fintype.

Also fix the name of Finset.mem_powerset_len_univ_iff (it should be powersetLen, not powerset_len).

94638cdb

Diff

@@ -26,29 +26,32 @@ theorem Fintype.card_finset [Fintype α] : Fintype.card (Finset α) = 2 ^ Fintyp
   Finset.card_powerset Finset.univ
 #align fintype.card_finset Fintype.card_finset
 
-@[simp]
-theorem Finset.powerset_univ [Fintype α] : (univ : Finset α).powerset = univ :=
+namespace Finset
+variable [Fintype α] {s : Finset α} {k : ℕ}
+
+@[simp] lemma powerset_univ : (univ : Finset α).powerset = univ :=
   coe_injective <| by simp [-coe_eq_univ]
 #align finset.powerset_univ Finset.powerset_univ
 
-@[simp]
-theorem Finset.powerset_eq_univ [Fintype α] {s : Finset α} : s.powerset = univ ↔ s = univ := by
+lemma filter_subset_univ [DecidableEq α] (s : Finset α) :
+    filter (fun t ↦ t ⊆ s) univ = powerset s := by ext; simp
+
+@[simp] lemma powerset_eq_univ : s.powerset = univ ↔ s = univ := by
   rw [← Finset.powerset_univ, powerset_inj]
 #align finset.powerset_eq_univ Finset.powerset_eq_univ
 
-@[simp]
-theorem Finset.mem_powerset_len_univ_iff [Fintype α] {s : Finset α} {k : ℕ} :
-    s ∈ powersetLen k (univ : Finset α) ↔ card s = k :=
+@[simp] lemma mem_powersetLen_univ : s ∈ powersetLen k (univ : Finset α) ↔ card s = k :=
   mem_powersetLen.trans <| and_iff_right <| subset_univ _
-#align finset.mem_powerset_len_univ_iff Finset.mem_powerset_len_univ_iff
+#align finset.mem_powerset_len_univ_iff Finset.mem_powersetLen_univ
 
-@[simp]
-theorem Finset.univ_filter_card_eq (α : Type*) [Fintype α] (k : ℕ) :
-    ((Finset.univ : Finset (Finset α)).filter fun s => s.card = k) = Finset.univ.powersetLen k := by
-  ext
-  simp [Finset.mem_powersetLen]
+variable (α)
+
+@[simp] lemma univ_filter_card_eq (k : ℕ) :
+    (univ : Finset (Finset α)).filter (fun s ↦ s.card = k) = univ.powersetLen k := by ext; simp
 #align finset.univ_filter_card_eq Finset.univ_filter_card_eq
 
+end Finset
+
 @[simp]
 theorem Fintype.card_finset_len [Fintype α] (k : ℕ) :
     Fintype.card { s : Finset α // s.card = k } = Nat.choose (Fintype.card α) k := by

509de852

feat(RingTheory/MvPolynomial/NewtonIdentities): Add proof of Newton's identities (#6139)

Co-authored-by: michaellee94 <michael.a.rodrigues.lee@gmail.com> Co-authored-by: Oliver Nash <github@olivernash.org>

63ae2f41

Diff

@@ -36,6 +36,7 @@ theorem Finset.powerset_eq_univ [Fintype α] {s : Finset α} : s.powerset = univ
   rw [← Finset.powerset_univ, powerset_inj]
 #align finset.powerset_eq_univ Finset.powerset_eq_univ
 
+@[simp]
 theorem Finset.mem_powerset_len_univ_iff [Fintype α] {s : Finset α} {k : ℕ} :
     s ∈ powersetLen k (univ : Finset α) ↔ card s = k :=
   mem_powersetLen.trans <| and_iff_right <| subset_univ _

509de852

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.Data.Finset.Powerset
 -/
 
 
-variable {α : Type _}
+variable {α : Type*}
 
 open Finset
 
@@ -42,7 +42,7 @@ theorem Finset.mem_powerset_len_univ_iff [Fintype α] {s : Finset α} {k : ℕ}
 #align finset.mem_powerset_len_univ_iff Finset.mem_powerset_len_univ_iff
 
 @[simp]
-theorem Finset.univ_filter_card_eq (α : Type _) [Fintype α] (k : ℕ) :
+theorem Finset.univ_filter_card_eq (α : Type*) [Fintype α] (k : ℕ) :
     ((Finset.univ : Finset (Finset α)).filter fun s => s.card = k) = Finset.univ.powersetLen k := by
   ext
   simp [Finset.mem_powersetLen]

509de852

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) 2017 Mario Carneiro. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Mario Carneiro
-
-! This file was ported from Lean 3 source module data.fintype.powerset
-! leanprover-community/mathlib commit 509de852e1de55e1efa8eacfa11df0823f26f226
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathlib.Data.Fintype.Card
 import Mathlib.Data.Finset.Powerset
 
+#align_import data.fintype.powerset from "leanprover-community/mathlib"@"509de852e1de55e1efa8eacfa11df0823f26f226"
+
 /-!
 # fintype instance for `Set α`, when `α` is a fintype
 -/

509de852

chore: bye-bye, solo bys! (#3825)

This PR puts, with one exception, every single remaining by that lies all by itself on its own line to the previous line, thus matching the current behaviour of start-port.sh. The exception is when the by begins the second or later argument to a tuple or anonymous constructor; see https://github.com/leanprover-community/mathlib4/pull/3825#discussion_r1186702599.

Essentially this is s/\n *by$/ by/g, but with manual editing to satisfy the linter's max-100-char-line requirement. The Python style linter is also modified to catch these "isolated bys".

14167e48

Diff

@@ -46,8 +46,7 @@ theorem Finset.mem_powerset_len_univ_iff [Fintype α] {s : Finset α} {k : ℕ}
 
 @[simp]
 theorem Finset.univ_filter_card_eq (α : Type _) [Fintype α] (k : ℕ) :
-    ((Finset.univ : Finset (Finset α)).filter fun s => s.card = k) = Finset.univ.powersetLen k :=
-  by
+    ((Finset.univ : Finset (Finset α)).filter fun s => s.card = k) = Finset.univ.powersetLen k := by
   ext
   simp [Finset.mem_powersetLen]
 #align finset.univ_filter_card_eq Finset.univ_filter_card_eq

509de852

chore: tidy various files (#1693)

cff6012d

Diff

@@ -67,7 +67,7 @@ instance Set.fintype [Fintype α] : Fintype (Set α) :=
       rfl⟩
 #align set.fintype Set.fintype
 
--- Not to be confused with `Set.finite`, the predicate
+-- Not to be confused with `Set.Finite`, the predicate
 instance Set.finite' [Finite α] : Finite (Set α) := by
   cases nonempty_fintype α
   infer_instance

509de852

feat: port Data.Fintype.Powerset (#1678)

351f8682

`data.fintype.powerset` ⟷ `Mathlib.Data.Fintype.Powerset`

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 2 + 182

data.fintype.powerset ⟷ Mathlib.Data.Fintype.Powerset

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 2 + 182

`data.fintype.powerset` ⟷ `Mathlib.Data.Fintype.Powerset`