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

2b35fc7b

(last sync)

Changes in mathlib3port

mathlib3

mathlib3port

ee05e9ce

bump to nightly-2024-04-25-08

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

ad7a2212

Diff

@@ -129,7 +129,7 @@ theorem IsSRGWith.card_neighborFinset_union_of_adj {v w : V} (h : G.IsSRGWith n
 theorem compl_neighborFinset_sdiff_inter_eq {v w : V} :
     G.neighborFinset vᶜ \ {v} ∩ (G.neighborFinset wᶜ \ {w}) =
       (G.neighborFinset vᶜ ∩ G.neighborFinset wᶜ) \ ({w} ∪ {v}) :=
-  by ext; rw [← not_iff_not]; simp [imp_iff_not_or, or_assoc', or_comm', or_left_comm]
+  by ext; rw [← not_iff_not]; simp [imp_iff_not_or, or_assoc, or_comm, or_left_comm]
 #align simple_graph.compl_neighbor_finset_sdiff_inter_eq SimpleGraph.compl_neighborFinset_sdiff_inter_eq
 -/

ee05e9ce

bump to nightly-2024-03-17-08

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

22f01ce4

Diff

@@ -163,7 +163,7 @@ theorem IsSRGWith.card_commonNeighbors_eq_of_adj_compl (h : G.IsSRGWith n k ℓ
     Set.toFinset_diff, Set.toFinset_singleton, Set.toFinset_compl, ← neighbor_finset_def]
   simp_rw [compl_neighbor_finset_sdiff_inter_eq]
   have hne : v ≠ w := ne_of_adj _ ha
-  rw [compl_adj] at ha 
+  rw [compl_adj] at ha
   rw [card_sdiff, ← insert_eq, card_insert_of_not_mem, card_singleton, ← Finset.compl_union]
   · change 1 + 1 with 2
     rw [card_compl, h.card_neighbor_finset_union_of_not_adj hne ha.2, ← h.card]
@@ -180,7 +180,7 @@ theorem IsSRGWith.card_commonNeighbors_eq_of_not_adj_compl (h : G.IsSRGWith n k
   by
   simp only [← Set.toFinset_card, common_neighbors, Set.toFinset_inter, neighbor_set_compl,
     Set.toFinset_diff, Set.toFinset_singleton, Set.toFinset_compl, ← neighbor_finset_def]
-  simp only [not_and, Classical.not_not, compl_adj] at hna 
+  simp only [not_and, Classical.not_not, compl_adj] at hna
   have h2' := hna hn
   simp_rw [compl_neighbor_finset_sdiff_inter_eq, sdiff_compl_neighbor_finset_inter_eq h2']
   rwa [← Finset.compl_union, card_compl, h.card_neighbor_finset_union_of_adj, ← h.card]

ee05e9ce

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 Alena Gusakov. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Alena Gusakov
 -/
-import Mathbin.Combinatorics.SimpleGraph.Basic
-import Mathbin.Data.Set.Finite
+import Combinatorics.SimpleGraph.Basic
+import Data.Set.Finite
 
 #align_import combinatorics.simple_graph.strongly_regular from "leanprover-community/mathlib"@"ee05e9ce1322178f0c12004eb93c00d2c8c00ed2"

ee05e9ce

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 Alena Gusakov. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Alena Gusakov
-
-! This file was ported from Lean 3 source module combinatorics.simple_graph.strongly_regular
-! leanprover-community/mathlib commit ee05e9ce1322178f0c12004eb93c00d2c8c00ed2
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathbin.Combinatorics.SimpleGraph.Basic
 import Mathbin.Data.Set.Finite
 
+#align_import combinatorics.simple_graph.strongly_regular from "leanprover-community/mathlib"@"ee05e9ce1322178f0c12004eb93c00d2c8c00ed2"
+
 /-!
 # Strongly regular graphs

ee05e9ce

bump to nightly-2023-06-13-21

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

829520ac

Diff

@@ -46,6 +46,7 @@ variable [Fintype V] [DecidableEq V]
 
 variable (G : SimpleGraph V) [DecidableRel G.Adj]
 
+#print SimpleGraph.IsSRGWith /-
 /-- A graph is strongly regular with parameters `n k ℓ μ` if
  * its vertex set has cardinality `n`
  * it is regular with degree `k`
@@ -58,9 +59,11 @@ structure IsSRGWith (n k ℓ μ : ℕ) : Prop where
   of_adj : ∀ v w : V, G.Adj v w → Fintype.card (G.commonNeighbors v w) = ℓ
   of_not_adj : ∀ v w : V, v ≠ w → ¬G.Adj v w → Fintype.card (G.commonNeighbors v w) = μ
 #align simple_graph.is_SRG_with SimpleGraph.IsSRGWith
+-/
 
 variable {G} {n k ℓ μ : ℕ}
 
+#print SimpleGraph.bot_strongly_regular /-
 /-- Empty graphs are strongly regular. Note that `ℓ` can take any value
   for empty graphs, since there are no pairs of adjacent vertices. -/
 theorem bot_strongly_regular : (⊥ : SimpleGraph V).IsSRGWith (Fintype.card V) 0 ℓ 0 :=
@@ -74,6 +77,7 @@ theorem bot_strongly_regular : (⊥ : SimpleGraph V).IsSRGWith (Fintype.card V)
       ext
       simp [mem_common_neighbors] }
 #align simple_graph.bot_strongly_regular SimpleGraph.bot_strongly_regular
+-/
 
 #print SimpleGraph.IsSRGWith.top /-
 /-- Complete graphs are strongly regular. Note that `μ` can take any value

ee05e9ce

bump to nightly-2023-06-01-16

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

b9c87c70

Diff

@@ -162,7 +162,7 @@ theorem IsSRGWith.card_commonNeighbors_eq_of_adj_compl (h : G.IsSRGWith n k ℓ
     Set.toFinset_diff, Set.toFinset_singleton, Set.toFinset_compl, ← neighbor_finset_def]
   simp_rw [compl_neighbor_finset_sdiff_inter_eq]
   have hne : v ≠ w := ne_of_adj _ ha
-  rw [compl_adj] at ha
+  rw [compl_adj] at ha 
   rw [card_sdiff, ← insert_eq, card_insert_of_not_mem, card_singleton, ← Finset.compl_union]
   · change 1 + 1 with 2
     rw [card_compl, h.card_neighbor_finset_union_of_not_adj hne ha.2, ← h.card]
@@ -179,7 +179,7 @@ theorem IsSRGWith.card_commonNeighbors_eq_of_not_adj_compl (h : G.IsSRGWith n k
   by
   simp only [← Set.toFinset_card, common_neighbors, Set.toFinset_inter, neighbor_set_compl,
     Set.toFinset_diff, Set.toFinset_singleton, Set.toFinset_compl, ← neighbor_finset_def]
-  simp only [not_and, Classical.not_not, compl_adj] at hna
+  simp only [not_and, Classical.not_not, compl_adj] at hna 
   have h2' := hna hn
   simp_rw [compl_neighbor_finset_sdiff_inter_eq, sdiff_compl_neighbor_finset_inter_eq h2']
   rwa [← Finset.compl_union, card_compl, h.card_neighbor_finset_union_of_adj, ← h.card]

ee05e9ce

bump to nightly-2023-05-28-06

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

ba5d8b97

Diff

@@ -46,12 +46,6 @@ variable [Fintype V] [DecidableEq V]
 
 variable (G : SimpleGraph V) [DecidableRel G.Adj]
 
-/- warning: simple_graph.is_SRG_with -> SimpleGraph.IsSRGWith is a dubious translation:
-lean 3 declaration is
-  forall {V : Type.{u1}} [_inst_1 : Fintype.{u1} V] [_inst_2 : DecidableEq.{succ u1} V] (G : SimpleGraph.{u1} V) [_inst_3 : DecidableRel.{succ u1} V (SimpleGraph.Adj.{u1} V G)], Nat -> Nat -> Nat -> Nat -> Prop
-but is expected to have type
-  forall {V : Type.{u1}} [_inst_1 : Fintype.{u1} V] (_inst_2 : SimpleGraph.{u1} V) [G : DecidableRel.{succ u1} V (SimpleGraph.Adj.{u1} V _inst_2)], Nat -> Nat -> Nat -> Nat -> Prop
-Case conversion may be inaccurate. Consider using '#align simple_graph.is_SRG_with SimpleGraph.IsSRGWithₓ'. -/
 /-- A graph is strongly regular with parameters `n k ℓ μ` if
  * its vertex set has cardinality `n`
  * it is regular with degree `k`
@@ -67,12 +61,6 @@ structure IsSRGWith (n k ℓ μ : ℕ) : Prop where
 
 variable {G} {n k ℓ μ : ℕ}
 
-/- warning: simple_graph.bot_strongly_regular -> SimpleGraph.bot_strongly_regular is a dubious translation:
-lean 3 declaration is
-  forall {V : Type.{u1}} [_inst_1 : Fintype.{u1} V] [_inst_2 : DecidableEq.{succ u1} V] {ℓ : Nat}, SimpleGraph.IsSRGWith.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b) (Bot.bot.{u1} (SimpleGraph.{u1} V) (CompleteLattice.toHasBot.{u1} (SimpleGraph.{u1} V) (Order.Coframe.toCompleteLattice.{u1} (SimpleGraph.{u1} V) (CompleteDistribLattice.toCoframe.{u1} (SimpleGraph.{u1} V) (CompleteBooleanAlgebra.toCompleteDistribLattice.{u1} (SimpleGraph.{u1} V) (SimpleGraph.completeBooleanAlgebra.{u1} V)))))) (fun (a : V) (b : V) => SimpleGraph.Bot.adjDecidable.{u1} V a b) (Fintype.card.{u1} V _inst_1) (OfNat.ofNat.{0} Nat 0 (OfNat.mk.{0} Nat 0 (Zero.zero.{0} Nat Nat.hasZero))) ℓ (OfNat.ofNat.{0} Nat 0 (OfNat.mk.{0} Nat 0 (Zero.zero.{0} Nat Nat.hasZero)))
-but is expected to have type
-  forall {V : Type.{u1}} [_inst_1 : Fintype.{u1} V] {_inst_2 : Nat}, SimpleGraph.IsSRGWith.{u1} V _inst_1 (Bot.bot.{u1} (SimpleGraph.{u1} V) (CompleteLattice.toBot.{u1} (SimpleGraph.{u1} V) (Order.Coframe.toCompleteLattice.{u1} (SimpleGraph.{u1} V) (CompleteDistribLattice.toCoframe.{u1} (SimpleGraph.{u1} V) (CompleteBooleanAlgebra.toCompleteDistribLattice.{u1} (SimpleGraph.{u1} V) (SimpleGraph.completeBooleanAlgebra.{u1} V)))))) (fun (a : V) (b : V) => SimpleGraph.Bot.adjDecidable.{u1} V a b) (Fintype.card.{u1} V _inst_1) (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0)) _inst_2 (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0))
-Case conversion may be inaccurate. Consider using '#align simple_graph.bot_strongly_regular SimpleGraph.bot_strongly_regularₓ'. -/
 /-- Empty graphs are strongly regular. Note that `ℓ` can take any value
   for empty graphs, since there are no pairs of adjacent vertices. -/
 theorem bot_strongly_regular : (⊥ : SimpleGraph V).IsSRGWith (Fintype.card V) 0 ℓ 0 :=

ee05e9ce

bump to nightly-2023-05-28-04

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

6797a637

Diff

@@ -140,10 +140,7 @@ theorem IsSRGWith.card_neighborFinset_union_of_adj {v w : V} (h : G.IsSRGWith n
 theorem compl_neighborFinset_sdiff_inter_eq {v w : V} :
     G.neighborFinset vᶜ \ {v} ∩ (G.neighborFinset wᶜ \ {w}) =
       (G.neighborFinset vᶜ ∩ G.neighborFinset wᶜ) \ ({w} ∪ {v}) :=
-  by
-  ext
-  rw [← not_iff_not]
-  simp [imp_iff_not_or, or_assoc', or_comm', or_left_comm]
+  by ext; rw [← not_iff_not]; simp [imp_iff_not_or, or_assoc', or_comm', or_left_comm]
 #align simple_graph.compl_neighbor_finset_sdiff_inter_eq SimpleGraph.compl_neighborFinset_sdiff_inter_eq
 -/
 
@@ -157,8 +154,7 @@ theorem sdiff_compl_neighborFinset_inter_eq {v w : V} (h : G.Adj v w) :
     mem_inter, mem_singleton]
   rintro hnv hnw (rfl | rfl)
   · exact hnv h
-  · apply hnw
-    rwa [adj_comm]
+  · apply hnw; rwa [adj_comm]
 #align simple_graph.sdiff_compl_neighbor_finset_inter_eq SimpleGraph.sdiff_compl_neighborFinset_inter_eq
 -/

ee05e9ce

bump to nightly-2023-03-27-22

mathlib commit https://github.com/leanprover-community/mathlib/commit/ce86f4e05e9a9b8da5e316b22c76ce76440c56a1

0f55b099

Diff

@@ -71,7 +71,7 @@ variable {G} {n k ℓ μ : ℕ}
 lean 3 declaration is
   forall {V : Type.{u1}} [_inst_1 : Fintype.{u1} V] [_inst_2 : DecidableEq.{succ u1} V] {ℓ : Nat}, SimpleGraph.IsSRGWith.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b) (Bot.bot.{u1} (SimpleGraph.{u1} V) (CompleteLattice.toHasBot.{u1} (SimpleGraph.{u1} V) (Order.Coframe.toCompleteLattice.{u1} (SimpleGraph.{u1} V) (CompleteDistribLattice.toCoframe.{u1} (SimpleGraph.{u1} V) (CompleteBooleanAlgebra.toCompleteDistribLattice.{u1} (SimpleGraph.{u1} V) (SimpleGraph.completeBooleanAlgebra.{u1} V)))))) (fun (a : V) (b : V) => SimpleGraph.Bot.adjDecidable.{u1} V a b) (Fintype.card.{u1} V _inst_1) (OfNat.ofNat.{0} Nat 0 (OfNat.mk.{0} Nat 0 (Zero.zero.{0} Nat Nat.hasZero))) ℓ (OfNat.ofNat.{0} Nat 0 (OfNat.mk.{0} Nat 0 (Zero.zero.{0} Nat Nat.hasZero)))
 but is expected to have type
-  forall {V : Type.{u1}} [_inst_1 : Fintype.{u1} V] {_inst_2 : Nat}, SimpleGraph.IsSRGWith.{u1} V _inst_1 (Bot.bot.{u1} (SimpleGraph.{u1} V) (BooleanAlgebra.toBot.{u1} (SimpleGraph.{u1} V) (SimpleGraph.instBooleanAlgebraSimpleGraph.{u1} V))) (fun (a : V) (b : V) => SimpleGraph.Bot.adjDecidable.{u1} V a b) (Fintype.card.{u1} V _inst_1) (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0)) _inst_2 (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0))
+  forall {V : Type.{u1}} [_inst_1 : Fintype.{u1} V] {_inst_2 : Nat}, SimpleGraph.IsSRGWith.{u1} V _inst_1 (Bot.bot.{u1} (SimpleGraph.{u1} V) (CompleteLattice.toBot.{u1} (SimpleGraph.{u1} V) (Order.Coframe.toCompleteLattice.{u1} (SimpleGraph.{u1} V) (CompleteDistribLattice.toCoframe.{u1} (SimpleGraph.{u1} V) (CompleteBooleanAlgebra.toCompleteDistribLattice.{u1} (SimpleGraph.{u1} V) (SimpleGraph.completeBooleanAlgebra.{u1} V)))))) (fun (a : V) (b : V) => SimpleGraph.Bot.adjDecidable.{u1} V a b) (Fintype.card.{u1} V _inst_1) (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0)) _inst_2 (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0))
 Case conversion may be inaccurate. Consider using '#align simple_graph.bot_strongly_regular SimpleGraph.bot_strongly_regularₓ'. -/
 /-- Empty graphs are strongly regular. Note that `ℓ` can take any value
   for empty graphs, since there are no pairs of adjacent vertices. -/

ee05e9ce

bump to nightly-2023-03-11-18

mathlib commit https://github.com/leanprover-community/mathlib/commit/3180fab693e2cee3bff62675571264cb8778b212

1d00e3b6

Diff

@@ -136,12 +136,7 @@ theorem IsSRGWith.card_neighborFinset_union_of_adj {v w : V} (h : G.IsSRGWith n
 #align simple_graph.is_SRG_with.card_neighbor_finset_union_of_adj SimpleGraph.IsSRGWith.card_neighborFinset_union_of_adj
 -/
 
-/- warning: simple_graph.compl_neighbor_finset_sdiff_inter_eq -> SimpleGraph.compl_neighborFinset_sdiff_inter_eq is a dubious translation:
-lean 3 declaration is
-  forall {V : Type.{u1}} [_inst_1 : Fintype.{u1} V] [_inst_2 : DecidableEq.{succ u1} V] {G : SimpleGraph.{u1} V} [_inst_3 : DecidableRel.{succ u1} V (SimpleGraph.Adj.{u1} V G)] {v : V} {w : V}, Eq.{succ u1} (Finset.{u1} V) (Inter.inter.{u1} (Finset.{u1} V) (Finset.hasInter.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (SDiff.sdiff.{u1} (Finset.{u1} V) (Finset.hasSdiff.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.booleanAlgebra.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G v (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) v))) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.hasSingleton.{u1} V) v)) (SDiff.sdiff.{u1} (Finset.{u1} V) (Finset.hasSdiff.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.booleanAlgebra.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G w (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) w))) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.hasSingleton.{u1} V) w))) (SDiff.sdiff.{u1} (Finset.{u1} V) (Finset.hasSdiff.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (Inter.inter.{u1} (Finset.{u1} V) (Finset.hasInter.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.booleanAlgebra.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G v (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) v))) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.booleanAlgebra.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G w (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) w)))) (Union.union.{u1} (Finset.{u1} V) (Finset.hasUnion.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.hasSingleton.{u1} V) w) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.hasSingleton.{u1} V) v)))
-but is expected to have type
-  forall {V : Type.{u1}} [_inst_1 : Fintype.{u1} V] [_inst_2 : DecidableEq.{succ u1} V] {G : SimpleGraph.{u1} V} [_inst_3 : DecidableRel.{succ u1} V (SimpleGraph.Adj.{u1} V G)] {v : V} {w : V}, Eq.{succ u1} (Finset.{u1} V) (Inter.inter.{u1} (Finset.{u1} V) (Finset.instInterFinset.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (SDiff.sdiff.{u1} (Finset.{u1} V) (Finset.instSDiffFinset.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.instBooleanAlgebraFinset.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G v (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) v))) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.instSingletonFinset.{u1} V) v)) (SDiff.sdiff.{u1} (Finset.{u1} V) (Finset.instSDiffFinset.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.instBooleanAlgebraFinset.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G w (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) w))) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.instSingletonFinset.{u1} V) w))) (SDiff.sdiff.{u1} (Finset.{u1} V) (Finset.instSDiffFinset.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (Inter.inter.{u1} (Finset.{u1} V) (Finset.instInterFinset.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.instBooleanAlgebraFinset.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G v (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) v))) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.instBooleanAlgebraFinset.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G w (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) w)))) (Union.union.{u1} (Finset.{u1} V) (Finset.instUnionFinset.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.instSingletonFinset.{u1} V) w) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.instSingletonFinset.{u1} V) v)))
-Case conversion may be inaccurate. Consider using '#align simple_graph.compl_neighbor_finset_sdiff_inter_eq SimpleGraph.compl_neighborFinset_sdiff_inter_eqₓ'. -/
+#print SimpleGraph.compl_neighborFinset_sdiff_inter_eq /-
 theorem compl_neighborFinset_sdiff_inter_eq {v w : V} :
     G.neighborFinset vᶜ \ {v} ∩ (G.neighborFinset wᶜ \ {w}) =
       (G.neighborFinset vᶜ ∩ G.neighborFinset wᶜ) \ ({w} ∪ {v}) :=
@@ -150,13 +145,9 @@ theorem compl_neighborFinset_sdiff_inter_eq {v w : V} :
   rw [← not_iff_not]
   simp [imp_iff_not_or, or_assoc', or_comm', or_left_comm]
 #align simple_graph.compl_neighbor_finset_sdiff_inter_eq SimpleGraph.compl_neighborFinset_sdiff_inter_eq
+-/
 
-/- warning: simple_graph.sdiff_compl_neighbor_finset_inter_eq -> SimpleGraph.sdiff_compl_neighborFinset_inter_eq is a dubious translation:
-lean 3 declaration is
-  forall {V : Type.{u1}} [_inst_1 : Fintype.{u1} V] [_inst_2 : DecidableEq.{succ u1} V] {G : SimpleGraph.{u1} V} [_inst_3 : DecidableRel.{succ u1} V (SimpleGraph.Adj.{u1} V G)] {v : V} {w : V}, (SimpleGraph.Adj.{u1} V G v w) -> (Eq.{succ u1} (Finset.{u1} V) (SDiff.sdiff.{u1} (Finset.{u1} V) (Finset.hasSdiff.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (Inter.inter.{u1} (Finset.{u1} V) (Finset.hasInter.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.booleanAlgebra.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G v (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) v))) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.booleanAlgebra.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G w (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) w)))) (Union.union.{u1} (Finset.{u1} V) (Finset.hasUnion.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.hasSingleton.{u1} V) w) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.hasSingleton.{u1} V) v))) (Inter.inter.{u1} (Finset.{u1} V) (Finset.hasInter.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.booleanAlgebra.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G v (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) v))) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.booleanAlgebra.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G w (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) w)))))
-but is expected to have type
-  forall {V : Type.{u1}} [_inst_1 : Fintype.{u1} V] [_inst_2 : DecidableEq.{succ u1} V] {G : SimpleGraph.{u1} V} [_inst_3 : DecidableRel.{succ u1} V (SimpleGraph.Adj.{u1} V G)] {v : V} {w : V}, (SimpleGraph.Adj.{u1} V G v w) -> (Eq.{succ u1} (Finset.{u1} V) (SDiff.sdiff.{u1} (Finset.{u1} V) (Finset.instSDiffFinset.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (Inter.inter.{u1} (Finset.{u1} V) (Finset.instInterFinset.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.instBooleanAlgebraFinset.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G v (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) v))) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.instBooleanAlgebraFinset.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G w (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) w)))) (Union.union.{u1} (Finset.{u1} V) (Finset.instUnionFinset.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.instSingletonFinset.{u1} V) w) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.instSingletonFinset.{u1} V) v))) (Inter.inter.{u1} (Finset.{u1} V) (Finset.instInterFinset.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.instBooleanAlgebraFinset.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G v (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) v))) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.instBooleanAlgebraFinset.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G w (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) w)))))
-Case conversion may be inaccurate. Consider using '#align simple_graph.sdiff_compl_neighbor_finset_inter_eq SimpleGraph.sdiff_compl_neighborFinset_inter_eqₓ'. -/
+#print SimpleGraph.sdiff_compl_neighborFinset_inter_eq /-
 theorem sdiff_compl_neighborFinset_inter_eq {v w : V} (h : G.Adj v w) :
     (G.neighborFinset vᶜ ∩ G.neighborFinset wᶜ) \ ({w} ∪ {v}) =
       G.neighborFinset vᶜ ∩ G.neighborFinset wᶜ :=
@@ -169,6 +160,7 @@ theorem sdiff_compl_neighborFinset_inter_eq {v w : V} (h : G.Adj v w) :
   · apply hnw
     rwa [adj_comm]
 #align simple_graph.sdiff_compl_neighbor_finset_inter_eq SimpleGraph.sdiff_compl_neighborFinset_inter_eq
+-/
 
 #print SimpleGraph.IsSRGWith.compl_is_regular /-
 theorem IsSRGWith.compl_is_regular (h : G.IsSRGWith n k ℓ μ) : Gᶜ.IsRegularOfDegree (n - k - 1) :=

ee05e9ce

bump to nightly-2023-03-02-03

mathlib commit https://github.com/leanprover-community/mathlib/commit/195fcd60ff2bfe392543bceb0ec2adcdb472db4c

db7421c3

Diff

@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Alena Gusakov
 
 ! This file was ported from Lean 3 source module combinatorics.simple_graph.strongly_regular
-! leanprover-community/mathlib commit 2b35fc7bea4640cb75e477e83f32fbd538920822
+! leanprover-community/mathlib commit ee05e9ce1322178f0c12004eb93c00d2c8c00ed2
 ! Please do not edit these lines, except to modify the commit id
 ! if you have ported upstream changes.
 -/
@@ -14,6 +14,9 @@ import Mathbin.Data.Set.Finite
 /-!
 # Strongly regular graphs
 
+> THIS FILE IS SYNCHRONIZED WITH MATHLIB4.
+> Any changes to this file require a corresponding PR to mathlib4.
+
 ## Main definitions
 
 * `G.is_SRG_with n k ℓ μ` (see `simple_graph.is_SRG_with`) is a structure for
@@ -66,7 +69,7 @@ variable {G} {n k ℓ μ : ℕ}
 
 /- warning: simple_graph.bot_strongly_regular -> SimpleGraph.bot_strongly_regular is a dubious translation:
 lean 3 declaration is
-  forall {V : Type.{u1}} [_inst_1 : Fintype.{u1} V] [_inst_2 : DecidableEq.{succ u1} V] {ℓ : Nat}, SimpleGraph.IsSRGWith.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b) (Bot.bot.{u1} (SimpleGraph.{u1} V) (BooleanAlgebra.toHasBot.{u1} (SimpleGraph.{u1} V) (SimpleGraph.booleanAlgebra.{u1} V))) (fun (a : V) (b : V) => SimpleGraph.Bot.adjDecidable.{u1} V a b) (Fintype.card.{u1} V _inst_1) (OfNat.ofNat.{0} Nat 0 (OfNat.mk.{0} Nat 0 (Zero.zero.{0} Nat Nat.hasZero))) ℓ (OfNat.ofNat.{0} Nat 0 (OfNat.mk.{0} Nat 0 (Zero.zero.{0} Nat Nat.hasZero)))
+  forall {V : Type.{u1}} [_inst_1 : Fintype.{u1} V] [_inst_2 : DecidableEq.{succ u1} V] {ℓ : Nat}, SimpleGraph.IsSRGWith.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b) (Bot.bot.{u1} (SimpleGraph.{u1} V) (CompleteLattice.toHasBot.{u1} (SimpleGraph.{u1} V) (Order.Coframe.toCompleteLattice.{u1} (SimpleGraph.{u1} V) (CompleteDistribLattice.toCoframe.{u1} (SimpleGraph.{u1} V) (CompleteBooleanAlgebra.toCompleteDistribLattice.{u1} (SimpleGraph.{u1} V) (SimpleGraph.completeBooleanAlgebra.{u1} V)))))) (fun (a : V) (b : V) => SimpleGraph.Bot.adjDecidable.{u1} V a b) (Fintype.card.{u1} V _inst_1) (OfNat.ofNat.{0} Nat 0 (OfNat.mk.{0} Nat 0 (Zero.zero.{0} Nat Nat.hasZero))) ℓ (OfNat.ofNat.{0} Nat 0 (OfNat.mk.{0} Nat 0 (Zero.zero.{0} Nat Nat.hasZero)))
 but is expected to have type
   forall {V : Type.{u1}} [_inst_1 : Fintype.{u1} V] {_inst_2 : Nat}, SimpleGraph.IsSRGWith.{u1} V _inst_1 (Bot.bot.{u1} (SimpleGraph.{u1} V) (BooleanAlgebra.toBot.{u1} (SimpleGraph.{u1} V) (SimpleGraph.instBooleanAlgebraSimpleGraph.{u1} V))) (fun (a : V) (b : V) => SimpleGraph.Bot.adjDecidable.{u1} V a b) (Fintype.card.{u1} V _inst_1) (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0)) _inst_2 (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0))
 Case conversion may be inaccurate. Consider using '#align simple_graph.bot_strongly_regular SimpleGraph.bot_strongly_regularₓ'. -/

2b35fc7b

bump to nightly-2023-02-27-16

mathlib commit https://github.com/leanprover-community/mathlib/commit/eb0cb4511aaef0da2462207b67358a0e1fe1e2ee

feafc24f

Diff

@@ -43,6 +43,12 @@ variable [Fintype V] [DecidableEq V]
 
 variable (G : SimpleGraph V) [DecidableRel G.Adj]
 
+/- warning: simple_graph.is_SRG_with -> SimpleGraph.IsSRGWith is a dubious translation:
+lean 3 declaration is
+  forall {V : Type.{u1}} [_inst_1 : Fintype.{u1} V] [_inst_2 : DecidableEq.{succ u1} V] (G : SimpleGraph.{u1} V) [_inst_3 : DecidableRel.{succ u1} V (SimpleGraph.Adj.{u1} V G)], Nat -> Nat -> Nat -> Nat -> Prop
+but is expected to have type
+  forall {V : Type.{u1}} [_inst_1 : Fintype.{u1} V] (_inst_2 : SimpleGraph.{u1} V) [G : DecidableRel.{succ u1} V (SimpleGraph.Adj.{u1} V _inst_2)], Nat -> Nat -> Nat -> Nat -> Prop
+Case conversion may be inaccurate. Consider using '#align simple_graph.is_SRG_with SimpleGraph.IsSRGWithₓ'. -/
 /-- A graph is strongly regular with parameters `n k ℓ μ` if
  * its vertex set has cardinality `n`
  * it is regular with degree `k`
@@ -58,6 +64,12 @@ structure IsSRGWith (n k ℓ μ : ℕ) : Prop where
 
 variable {G} {n k ℓ μ : ℕ}
 
+/- warning: simple_graph.bot_strongly_regular -> SimpleGraph.bot_strongly_regular is a dubious translation:
+lean 3 declaration is
+  forall {V : Type.{u1}} [_inst_1 : Fintype.{u1} V] [_inst_2 : DecidableEq.{succ u1} V] {ℓ : Nat}, SimpleGraph.IsSRGWith.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b) (Bot.bot.{u1} (SimpleGraph.{u1} V) (BooleanAlgebra.toHasBot.{u1} (SimpleGraph.{u1} V) (SimpleGraph.booleanAlgebra.{u1} V))) (fun (a : V) (b : V) => SimpleGraph.Bot.adjDecidable.{u1} V a b) (Fintype.card.{u1} V _inst_1) (OfNat.ofNat.{0} Nat 0 (OfNat.mk.{0} Nat 0 (Zero.zero.{0} Nat Nat.hasZero))) ℓ (OfNat.ofNat.{0} Nat 0 (OfNat.mk.{0} Nat 0 (Zero.zero.{0} Nat Nat.hasZero)))
+but is expected to have type
+  forall {V : Type.{u1}} [_inst_1 : Fintype.{u1} V] {_inst_2 : Nat}, SimpleGraph.IsSRGWith.{u1} V _inst_1 (Bot.bot.{u1} (SimpleGraph.{u1} V) (BooleanAlgebra.toBot.{u1} (SimpleGraph.{u1} V) (SimpleGraph.instBooleanAlgebraSimpleGraph.{u1} V))) (fun (a : V) (b : V) => SimpleGraph.Bot.adjDecidable.{u1} V a b) (Fintype.card.{u1} V _inst_1) (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0)) _inst_2 (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0))
+Case conversion may be inaccurate. Consider using '#align simple_graph.bot_strongly_regular SimpleGraph.bot_strongly_regularₓ'. -/
 /-- Empty graphs are strongly regular. Note that `ℓ` can take any value
   for empty graphs, since there are no pairs of adjacent vertices. -/
 theorem bot_strongly_regular : (⊥ : SimpleGraph V).IsSRGWith (Fintype.card V) 0 ℓ 0 :=
@@ -72,6 +84,7 @@ theorem bot_strongly_regular : (⊥ : SimpleGraph V).IsSRGWith (Fintype.card V)
       simp [mem_common_neighbors] }
 #align simple_graph.bot_strongly_regular SimpleGraph.bot_strongly_regular
 
+#print SimpleGraph.IsSRGWith.top /-
 /-- Complete graphs are strongly regular. Note that `μ` can take any value
   for complete graphs, since there are no distinct pairs of non-adjacent vertices. -/
 theorem IsSRGWith.top :
@@ -83,7 +96,9 @@ theorem IsSRGWith.top :
       exact h
     of_not_adj := fun v w h h' => False.elim <| by simpa using h }
 #align simple_graph.is_SRG_with.top SimpleGraph.IsSRGWith.top
+-/
 
+#print SimpleGraph.IsSRGWith.card_neighborFinset_union_eq /-
 theorem IsSRGWith.card_neighborFinset_union_eq {v w : V} (h : G.IsSRGWith n k ℓ μ) :
     (G.neighborFinset v ∪ G.neighborFinset w).card = 2 * k - Fintype.card (G.commonNeighbors v w) :=
   by
@@ -95,7 +110,9 @@ theorem IsSRGWith.card_neighborFinset_union_eq {v w : V} (h : G.IsSRGWith n k 
   · apply le_trans (card_common_neighbors_le_degree_left _ _ _)
     simp [h.regular.degree_eq, two_mul]
 #align simple_graph.is_SRG_with.card_neighbor_finset_union_eq SimpleGraph.IsSRGWith.card_neighborFinset_union_eq
+-/
 
+#print SimpleGraph.IsSRGWith.card_neighborFinset_union_of_not_adj /-
 /-- Assuming `G` is strongly regular, `2*(k + 1) - m` in `G` is the number of vertices that are
   adjacent to either `v` or `w` when `¬G.adj v w`. So it's the cardinality of
   `G.neighbor_set v ∪ G.neighbor_set w`. -/
@@ -105,14 +122,23 @@ theorem IsSRGWith.card_neighborFinset_union_of_not_adj {v w : V} (h : G.IsSRGWit
   rw [← h.of_not_adj v w hne ha]
   apply h.card_neighbor_finset_union_eq
 #align simple_graph.is_SRG_with.card_neighbor_finset_union_of_not_adj SimpleGraph.IsSRGWith.card_neighborFinset_union_of_not_adj
+-/
 
+#print SimpleGraph.IsSRGWith.card_neighborFinset_union_of_adj /-
 theorem IsSRGWith.card_neighborFinset_union_of_adj {v w : V} (h : G.IsSRGWith n k ℓ μ)
     (ha : G.Adj v w) : (G.neighborFinset v ∪ G.neighborFinset w).card = 2 * k - ℓ :=
   by
   rw [← h.of_adj v w ha]
   apply h.card_neighbor_finset_union_eq
 #align simple_graph.is_SRG_with.card_neighbor_finset_union_of_adj SimpleGraph.IsSRGWith.card_neighborFinset_union_of_adj
+-/
 
+/- warning: simple_graph.compl_neighbor_finset_sdiff_inter_eq -> SimpleGraph.compl_neighborFinset_sdiff_inter_eq is a dubious translation:
+lean 3 declaration is
+  forall {V : Type.{u1}} [_inst_1 : Fintype.{u1} V] [_inst_2 : DecidableEq.{succ u1} V] {G : SimpleGraph.{u1} V} [_inst_3 : DecidableRel.{succ u1} V (SimpleGraph.Adj.{u1} V G)] {v : V} {w : V}, Eq.{succ u1} (Finset.{u1} V) (Inter.inter.{u1} (Finset.{u1} V) (Finset.hasInter.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (SDiff.sdiff.{u1} (Finset.{u1} V) (Finset.hasSdiff.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.booleanAlgebra.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G v (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) v))) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.hasSingleton.{u1} V) v)) (SDiff.sdiff.{u1} (Finset.{u1} V) (Finset.hasSdiff.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.booleanAlgebra.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G w (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) w))) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.hasSingleton.{u1} V) w))) (SDiff.sdiff.{u1} (Finset.{u1} V) (Finset.hasSdiff.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (Inter.inter.{u1} (Finset.{u1} V) (Finset.hasInter.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.booleanAlgebra.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G v (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) v))) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.booleanAlgebra.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G w (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) w)))) (Union.union.{u1} (Finset.{u1} V) (Finset.hasUnion.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.hasSingleton.{u1} V) w) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.hasSingleton.{u1} V) v)))
+but is expected to have type
+  forall {V : Type.{u1}} [_inst_1 : Fintype.{u1} V] [_inst_2 : DecidableEq.{succ u1} V] {G : SimpleGraph.{u1} V} [_inst_3 : DecidableRel.{succ u1} V (SimpleGraph.Adj.{u1} V G)] {v : V} {w : V}, Eq.{succ u1} (Finset.{u1} V) (Inter.inter.{u1} (Finset.{u1} V) (Finset.instInterFinset.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (SDiff.sdiff.{u1} (Finset.{u1} V) (Finset.instSDiffFinset.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.instBooleanAlgebraFinset.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G v (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) v))) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.instSingletonFinset.{u1} V) v)) (SDiff.sdiff.{u1} (Finset.{u1} V) (Finset.instSDiffFinset.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.instBooleanAlgebraFinset.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G w (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) w))) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.instSingletonFinset.{u1} V) w))) (SDiff.sdiff.{u1} (Finset.{u1} V) (Finset.instSDiffFinset.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (Inter.inter.{u1} (Finset.{u1} V) (Finset.instInterFinset.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.instBooleanAlgebraFinset.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G v (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) v))) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.instBooleanAlgebraFinset.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G w (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) w)))) (Union.union.{u1} (Finset.{u1} V) (Finset.instUnionFinset.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.instSingletonFinset.{u1} V) w) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.instSingletonFinset.{u1} V) v)))
+Case conversion may be inaccurate. Consider using '#align simple_graph.compl_neighbor_finset_sdiff_inter_eq SimpleGraph.compl_neighborFinset_sdiff_inter_eqₓ'. -/
 theorem compl_neighborFinset_sdiff_inter_eq {v w : V} :
     G.neighborFinset vᶜ \ {v} ∩ (G.neighborFinset wᶜ \ {w}) =
       (G.neighborFinset vᶜ ∩ G.neighborFinset wᶜ) \ ({w} ∪ {v}) :=
@@ -122,6 +148,12 @@ theorem compl_neighborFinset_sdiff_inter_eq {v w : V} :
   simp [imp_iff_not_or, or_assoc', or_comm', or_left_comm]
 #align simple_graph.compl_neighbor_finset_sdiff_inter_eq SimpleGraph.compl_neighborFinset_sdiff_inter_eq
 
+/- warning: simple_graph.sdiff_compl_neighbor_finset_inter_eq -> SimpleGraph.sdiff_compl_neighborFinset_inter_eq is a dubious translation:
+lean 3 declaration is
+  forall {V : Type.{u1}} [_inst_1 : Fintype.{u1} V] [_inst_2 : DecidableEq.{succ u1} V] {G : SimpleGraph.{u1} V} [_inst_3 : DecidableRel.{succ u1} V (SimpleGraph.Adj.{u1} V G)] {v : V} {w : V}, (SimpleGraph.Adj.{u1} V G v w) -> (Eq.{succ u1} (Finset.{u1} V) (SDiff.sdiff.{u1} (Finset.{u1} V) (Finset.hasSdiff.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (Inter.inter.{u1} (Finset.{u1} V) (Finset.hasInter.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.booleanAlgebra.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G v (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) v))) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.booleanAlgebra.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G w (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) w)))) (Union.union.{u1} (Finset.{u1} V) (Finset.hasUnion.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.hasSingleton.{u1} V) w) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.hasSingleton.{u1} V) v))) (Inter.inter.{u1} (Finset.{u1} V) (Finset.hasInter.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.booleanAlgebra.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G v (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) v))) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.booleanAlgebra.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G w (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) w)))))
+but is expected to have type
+  forall {V : Type.{u1}} [_inst_1 : Fintype.{u1} V] [_inst_2 : DecidableEq.{succ u1} V] {G : SimpleGraph.{u1} V} [_inst_3 : DecidableRel.{succ u1} V (SimpleGraph.Adj.{u1} V G)] {v : V} {w : V}, (SimpleGraph.Adj.{u1} V G v w) -> (Eq.{succ u1} (Finset.{u1} V) (SDiff.sdiff.{u1} (Finset.{u1} V) (Finset.instSDiffFinset.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (Inter.inter.{u1} (Finset.{u1} V) (Finset.instInterFinset.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.instBooleanAlgebraFinset.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G v (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) v))) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.instBooleanAlgebraFinset.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G w (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) w)))) (Union.union.{u1} (Finset.{u1} V) (Finset.instUnionFinset.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.instSingletonFinset.{u1} V) w) (Singleton.singleton.{u1, u1} V (Finset.{u1} V) (Finset.instSingletonFinset.{u1} V) v))) (Inter.inter.{u1} (Finset.{u1} V) (Finset.instInterFinset.{u1} V (fun (a : V) (b : V) => _inst_2 a b)) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.instBooleanAlgebraFinset.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G v (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) v))) (HasCompl.compl.{u1} (Finset.{u1} V) (BooleanAlgebra.toHasCompl.{u1} (Finset.{u1} V) (Finset.instBooleanAlgebraFinset.{u1} V _inst_1 (fun (a : V) (b : V) => _inst_2 a b))) (SimpleGraph.neighborFinset.{u1} V G w (SimpleGraph.neighborSetFintype.{u1} V G _inst_1 (fun (a : V) (b : V) => _inst_3 a b) w)))))
+Case conversion may be inaccurate. Consider using '#align simple_graph.sdiff_compl_neighbor_finset_inter_eq SimpleGraph.sdiff_compl_neighborFinset_inter_eqₓ'. -/
 theorem sdiff_compl_neighborFinset_inter_eq {v w : V} (h : G.Adj v w) :
     (G.neighborFinset vᶜ ∩ G.neighborFinset wᶜ) \ ({w} ∪ {v}) =
       G.neighborFinset vᶜ ∩ G.neighborFinset wᶜ :=
@@ -135,12 +167,15 @@ theorem sdiff_compl_neighborFinset_inter_eq {v w : V} (h : G.Adj v w) :
     rwa [adj_comm]
 #align simple_graph.sdiff_compl_neighbor_finset_inter_eq SimpleGraph.sdiff_compl_neighborFinset_inter_eq
 
+#print SimpleGraph.IsSRGWith.compl_is_regular /-
 theorem IsSRGWith.compl_is_regular (h : G.IsSRGWith n k ℓ μ) : Gᶜ.IsRegularOfDegree (n - k - 1) :=
   by
   rw [← h.card, Nat.sub_sub, add_comm, ← Nat.sub_sub]
   exact h.regular.compl
 #align simple_graph.is_SRG_with.compl_is_regular SimpleGraph.IsSRGWith.compl_is_regular
+-/
 
+#print SimpleGraph.IsSRGWith.card_commonNeighbors_eq_of_adj_compl /-
 theorem IsSRGWith.card_commonNeighbors_eq_of_adj_compl (h : G.IsSRGWith n k ℓ μ) {v w : V}
     (ha : Gᶜ.Adj v w) : Fintype.card ↥(Gᶜ.commonNeighbors v w) = n - (2 * k - μ) - 2 :=
   by
@@ -157,7 +192,9 @@ theorem IsSRGWith.card_commonNeighbors_eq_of_adj_compl (h : G.IsSRGWith n k ℓ
     simp only [mem_union, mem_compl, mem_neighbor_finset, mem_inter, mem_singleton]
     rintro (rfl | rfl) <;> simpa [adj_comm] using ha.2
 #align simple_graph.is_SRG_with.card_common_neighbors_eq_of_adj_compl SimpleGraph.IsSRGWith.card_commonNeighbors_eq_of_adj_compl
+-/
 
+#print SimpleGraph.IsSRGWith.card_commonNeighbors_eq_of_not_adj_compl /-
 theorem IsSRGWith.card_commonNeighbors_eq_of_not_adj_compl (h : G.IsSRGWith n k ℓ μ) {v w : V}
     (hn : v ≠ w) (hna : ¬Gᶜ.Adj v w) : Fintype.card ↥(Gᶜ.commonNeighbors v w) = n - (2 * k - ℓ) :=
   by
@@ -168,7 +205,9 @@ theorem IsSRGWith.card_commonNeighbors_eq_of_not_adj_compl (h : G.IsSRGWith n k
   simp_rw [compl_neighbor_finset_sdiff_inter_eq, sdiff_compl_neighbor_finset_inter_eq h2']
   rwa [← Finset.compl_union, card_compl, h.card_neighbor_finset_union_of_adj, ← h.card]
 #align simple_graph.is_SRG_with.card_common_neighbors_eq_of_not_adj_compl SimpleGraph.IsSRGWith.card_commonNeighbors_eq_of_not_adj_compl
+-/
 
+#print SimpleGraph.IsSRGWith.compl /-
 /-- The complement of a strongly regular graph is strongly regular. -/
 theorem IsSRGWith.compl (h : G.IsSRGWith n k ℓ μ) :
     Gᶜ.IsSRGWith n (n - k - 1) (n - (2 * k - μ) - 2) (n - (2 * k - ℓ)) :=
@@ -177,6 +216,7 @@ theorem IsSRGWith.compl (h : G.IsSRGWith n k ℓ μ) :
     of_adj := fun v w ha => h.card_commonNeighbors_eq_of_adj_compl ha
     of_not_adj := fun v w hn hna => h.card_commonNeighbors_eq_of_not_adj_compl hn hna }
 #align simple_graph.is_SRG_with.compl SimpleGraph.IsSRGWith.compl
+-/
 
 end SimpleGraph

2b35fc7b

bump to nightly-2023-02-21-16

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

1107b979

Changes in mathlib4

mathlib3

mathlib4

2b35fc7b

chore(SimpleGraph): fix 3 DecidableEq assumptions (#11762)

Found by a WIP linter in #10235

3cecb823

Diff

@@ -183,6 +183,7 @@ set_option linter.uppercaseLean3 false in
 `k * (k - ℓ - 1) = (n - k - 1) * μ`. -/
 theorem IsSRGWith.param_eq (h : G.IsSRGWith n k ℓ μ) (hn : 0 < n) :
     k * (k - ℓ - 1) = (n - k - 1) * μ := by
+  letI := Classical.decEq V
   rw [← h.card, Fintype.card_pos_iff] at hn
   obtain ⟨v⟩ := hn
   convert card_mul_eq_card_mul G.Adj (s := G.neighborFinset v) (t := Gᶜ.neighborFinset v) _ _

2b35fc7b

move(Combinatorics/Enumerative): Create folder (#11666)

Move Catalan, Composition, DoubleCounting, Partition to a new folder Combinatorics.Enumerative.

eec91f37

Diff

@@ -3,7 +3,7 @@ Copyright (c) 2021 Alena Gusakov. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Alena Gusakov, Jeremy Tan
 -/
-import Mathlib.Combinatorics.DoubleCounting
+import Mathlib.Combinatorics.Enumerative.DoubleCounting
 import Mathlib.Combinatorics.SimpleGraph.AdjMatrix
 import Mathlib.Combinatorics.SimpleGraph.Basic
 import Mathlib.Data.Set.Finite

2b35fc7b

style: homogenise porting notes (#11145)

Homogenises porting notes via capitalisation and addition of whitespace.

It makes the following changes:

converts "--porting note" into "-- Porting note";
converts "porting note" into "Porting note".

8be0b69c

Diff

@@ -86,7 +86,7 @@ theorem IsSRGWith.card_neighborFinset_union_eq {v w : V} (h : G.IsSRGWith n k 
       2 * k - Fintype.card (G.commonNeighbors v w) := by
   apply Nat.add_right_cancel (m := Fintype.card (G.commonNeighbors v w))
   rw [Nat.sub_add_cancel, ← Set.toFinset_card]
-  -- porting note: Set.toFinset_inter needs workaround to use unification to solve for one of the
+  -- Porting note: Set.toFinset_inter needs workaround to use unification to solve for one of the
   -- instance arguments:
   · simp [commonNeighbors, @Set.toFinset_inter _ _ _ _ _ _ (_),
       ← neighborFinset_def, Finset.card_union_add_card_inter, card_neighborFinset_eq_degree,

2b35fc7b

chore: move to v4.6.0-rc1, merging adaptations from bump/v4.6.0 (#10176)

Co-authored-by: Scott Morrison <scott.morrison@gmail.com> Co-authored-by: Eric Wieser <wieser.eric@gmail.com> Co-authored-by: Joachim Breitner <mail@joachim-breitner.de>

490d2d48

Diff

@@ -190,8 +190,11 @@ theorem IsSRGWith.param_eq (h : G.IsSRGWith n k ℓ μ) (hn : 0 < n) :
   · simp [h.compl.regular v]
   · intro w hw
     rw [mem_neighborFinset] at hw
-    simp_rw [bipartiteAbove, show G.Adj w = fun a => G.Adj w a by rfl, ← mem_neighborFinset,
-      filter_mem_eq_inter]
+    simp_rw [bipartiteAbove]
+    -- This used to be part of the enclosing `simp_rw` chain,
+    -- but after leanprover/lean4#3124 it caused a maximum recursion depth error.
+    change Finset.card (filter (fun a => Adj G w a) _) = _
+    simp_rw [← mem_neighborFinset, filter_mem_eq_inter]
     have s : {v} ⊆ G.neighborFinset w \ G.neighborFinset v := by
       rw [singleton_subset_iff, mem_sdiff, mem_neighborFinset]
       exact ⟨hw.symm, G.not_mem_neighborFinset_self v⟩

2b35fc7b

refactor: Use Pairwise wherever possible (#9236)

Performed with a regex search for ∀ (.) (.), \1 ≠ \2 →, and a few variants to catch implicit binders and explicit types.

I have deliberately avoided trying to make the analogous Set.Pairwise transformation (or any Pairwise (foo on bar) transformations) in this PR, to keep the diff small.

Co-authored-by: Yaël Dillies <yael.dillies@gmail.com>

86393c89

Diff

@@ -50,7 +50,7 @@ structure IsSRGWith (n k ℓ μ : ℕ) : Prop where
   card : Fintype.card V = n
   regular : G.IsRegularOfDegree k
   of_adj : ∀ v w : V, G.Adj v w → Fintype.card (G.commonNeighbors v w) = ℓ
-  of_not_adj : ∀ v w : V, v ≠ w → ¬G.Adj v w → Fintype.card (G.commonNeighbors v w) = μ
+  of_not_adj : Pairwise fun v w => ¬G.Adj v w → Fintype.card (G.commonNeighbors v w) = μ
 set_option linter.uppercaseLean3 false in
 #align simple_graph.is_SRG_with SimpleGraph.IsSRGWith
 
@@ -102,7 +102,7 @@ adjacent to either `v` or `w` when `¬G.Adj v w`. So it's the cardinality of
 theorem IsSRGWith.card_neighborFinset_union_of_not_adj {v w : V} (h : G.IsSRGWith n k ℓ μ)
     (hne : v ≠ w) (ha : ¬G.Adj v w) :
     (G.neighborFinset v ∪ G.neighborFinset w).card = 2 * k - μ := by
-  rw [← h.of_not_adj v w hne ha]
+  rw [← h.of_not_adj hne ha]
   apply h.card_neighborFinset_union_eq
 set_option linter.uppercaseLean3 false in
 #align simple_graph.is_SRG_with.card_neighbor_finset_union_of_not_adj SimpleGraph.IsSRGWith.card_neighborFinset_union_of_not_adj
@@ -206,7 +206,7 @@ theorem IsSRGWith.param_eq (h : G.IsSRGWith n k ℓ μ) (hn : 0 < n) :
     simp_rw [neighborFinset_compl, mem_sdiff, mem_compl, mem_singleton, mem_neighborFinset,
       ← Ne.def] at hw
     simp_rw [bipartiteBelow, adj_comm, ← mem_neighborFinset, filter_mem_eq_inter,
-      neighborFinset_def, ← Set.toFinset_inter, ← h.of_not_adj v w hw.2.symm hw.1,
+      neighborFinset_def, ← Set.toFinset_inter, ← h.of_not_adj hw.2.symm hw.1,
       ← Set.toFinset_card]
     congr!
 
@@ -228,6 +228,6 @@ theorem IsSRGWith.matrix_eq {α : Type*} [Semiring α] (h : G.IsSRGWith n k ℓ
       simp only [ha, ite_true, ite_false, add_zero, zero_add, nsmul_eq_mul, smul_zero, mul_one,
         not_true_eq_false, not_false_eq_true, and_false, and_self]
     · rw [h.of_adj v w ha]
-    · rw [h.of_not_adj v w hn ha]
+    · rw [h.of_not_adj hn ha]
 
 end SimpleGraph

2b35fc7b

chore: bump to v4.3.0-rc2 (#8366)

PR contents

This is the supremum of

#8284
#8056
#8023
#8332
#8226 (already approved)
#7834 (already approved)

along with some minor fixes from failures on nightly-testing as Mathlib master is merged into it.

Note that some PRs for changes that are already compatible with the current toolchain and will be necessary have already been split out: #8380.

I am hopeful that in future we will be able to progressively merge adaptation PRs into a bump/v4.X.0 branch, so we never end up with a "big merge" like this. However one of these adaptation PRs (#8056) predates my new scheme for combined CI, and it wasn't possible to keep that PR viable in the meantime.

Lean PRs involved in this bump

In particular this includes adjustments for the Lean PRs

leanprover/lean4#2778

We can get rid of all the

local macro_rules | `($x ^ $y) => `(HPow.hPow $x $y) -- Porting note: See issue [lean4#2220](https://github.com/leanprover/lean4/pull/2220)

macros across Mathlib (and in any projects that want to write natural number powers of reals).

leanprover/lean4#2722

Changes the default behaviour of simp to (config := {decide := false}). This makes simp (and consequentially norm_num) less powerful, but also more consistent, and less likely to blow up in long failures. This requires a variety of changes: changing some previously by simp or norm_num to decide or rfl, or adding (config := {decide := true}).

leanprover/lean4#2783

This changed the behaviour of simp so that simp [f] will only unfold "fully applied" occurrences of f. The old behaviour can be recovered with simp (config := { unfoldPartialApp := true }). We may in future add a syntax for this, e.g. simp [!f]; please provide feedback! In the meantime, we have made the following changes:

switching to using explicit lemmas that have the intended level of application
(config := { unfoldPartialApp := true }) in some places, to recover the old behaviour
Using @[eqns] to manually adjust the equation lemmas for a particular definition, recovering the old behaviour just for that definition. See #8371, where we do this for Function.comp and Function.flip.

This change in Lean may require further changes down the line (e.g. adding the !f syntax, and/or upstreaming the special treatment for Function.comp and Function.flip, and/or removing this special treatment). Please keep an open and skeptical mind about these changes!

Co-authored-by: leanprover-community-mathlib4-bot <leanprover-community-mathlib4-bot@users.noreply.github.com> Co-authored-by: Scott Morrison <scott.morrison@gmail.com> Co-authored-by: Eric Wieser <wieser.eric@gmail.com> Co-authored-by: Mauricio Collares <mauricio@collares.org>

40b64f79

Diff

@@ -225,7 +225,8 @@ theorem IsSRGWith.matrix_eq {α : Type*} [Semiring α] (h : G.IsSRGWith n k ℓ
     simp [commonNeighbors, ← neighborFinset_def, h.regular v]
   · simp only [Matrix.one_apply_ne' hn.symm, ne_eq, hn]
     by_cases ha : G.Adj v w <;>
-      simp only [ha, ite_true, ite_false, add_zero, zero_add, nsmul_eq_mul, smul_zero, mul_one]
+      simp only [ha, ite_true, ite_false, add_zero, zero_add, nsmul_eq_mul, smul_zero, mul_one,
+        not_true_eq_false, not_false_eq_true, and_false, and_self]
     · rw [h.of_adj v w ha]
     · rw [h.of_not_adj v w hn ha]

2b35fc7b

chore: only four spaces for subsequent lines (#7286)

Co-authored-by: Moritz Firsching <firsching@google.com>

0c7d6fa5

Diff

@@ -135,7 +135,7 @@ theorem sdiff_compl_neighborFinset_inter_eq {v w : V} (h : G.Adj v w) :
 #align simple_graph.sdiff_compl_neighbor_finset_inter_eq SimpleGraph.sdiff_compl_neighborFinset_inter_eq
 
 theorem IsSRGWith.compl_is_regular (h : G.IsSRGWith n k ℓ μ) :
-  Gᶜ.IsRegularOfDegree (n - k - 1) := by
+    Gᶜ.IsRegularOfDegree (n - k - 1) := by
   rw [← h.card, Nat.sub_sub, add_comm, ← Nat.sub_sub]
   exact h.regular.compl
 set_option linter.uppercaseLean3 false in

2b35fc7b

feat: matrix equality of strongly regular graphs (#6507)

dcc92db9

Diff

@@ -1,11 +1,12 @@
 /-
 Copyright (c) 2021 Alena Gusakov. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Alena Gusakov
+Authors: Alena Gusakov, Jeremy Tan
 -/
+import Mathlib.Combinatorics.DoubleCounting
+import Mathlib.Combinatorics.SimpleGraph.AdjMatrix
 import Mathlib.Combinatorics.SimpleGraph.Basic
 import Mathlib.Data.Set.Finite
-import Mathlib.Combinatorics.DoubleCounting
 
 #align_import combinatorics.simple_graph.strongly_regular from "leanprover-community/mathlib"@"2b35fc7bea4640cb75e477e83f32fbd538920822"
 
@@ -21,9 +22,12 @@ import Mathlib.Combinatorics.DoubleCounting
   * The number of common neighbors between any two adjacent vertices in `G` is `ℓ`
   * The number of common neighbors between any two nonadjacent vertices in `G` is `μ`
 
-## TODO
-- Prove that if `I` is the identity matrix and `J` is the all-one matrix,
-  then the adj matrix `A` of SRG obeys relation `A^2 = kI + ℓA + μ(J - I - A)`
+## Main theorems
+
+* `IsSRGWith.compl`: the complement of a strongly regular graph is strongly regular.
+* `IsSRGWith.param_eq`: `k * (k - ℓ - 1) = (n - k - 1) * μ` when `0 < n`.
+* `IsSRGWith.matrix_eq`: let `A` and `C` be `G`'s and `Gᶜ`'s adjacency matrices respectively and
+  `I` be the identity matrix, then `A ^ 2 = k • I + ℓ • A + μ • C`.
 -/
 
 
@@ -206,4 +210,23 @@ theorem IsSRGWith.param_eq (h : G.IsSRGWith n k ℓ μ) (hn : 0 < n) :
       ← Set.toFinset_card]
     congr!
 
+/-- Let `A` and `C` be the adjacency matrices of a strongly regular graph with parameters `n k ℓ μ`
+and its complement respectively and `I` be the identity matrix,
+then `A ^ 2 = k • I + ℓ • A + μ • C`. `C` is equivalent to the expression `J - I - A`
+more often found in the literature, where `J` is the all-ones matrix. -/
+theorem IsSRGWith.matrix_eq {α : Type*} [Semiring α] (h : G.IsSRGWith n k ℓ μ) :
+    G.adjMatrix α ^ 2 = k • (1 : Matrix V V α) + ℓ • G.adjMatrix α + μ • Gᶜ.adjMatrix α := by
+  ext v w
+  simp only [adjMatrix_pow_apply_eq_card_walk, Set.coe_setOf, Matrix.add_apply, Matrix.smul_apply,
+    adjMatrix_apply, compl_adj]
+  rw [Fintype.card_congr (G.walkLengthTwoEquivCommonNeighbors v w)]
+  obtain rfl | hn := eq_or_ne v w
+  · rw [← Set.toFinset_card]
+    simp [commonNeighbors, ← neighborFinset_def, h.regular v]
+  · simp only [Matrix.one_apply_ne' hn.symm, ne_eq, hn]
+    by_cases ha : G.Adj v w <;>
+      simp only [ha, ite_true, ite_false, add_zero, zero_add, nsmul_eq_mul, smul_zero, mul_one]
+    · rw [h.of_adj v w ha]
+    · rw [h.of_not_adj v w hn ha]
+
 end SimpleGraph

2b35fc7b

feat: parameter equality of strongly regular graphs (#6060)

i.e. $k(k-l-1)=(n-k-1)μ$. An extra condition $n>0$ is required because the proof (a standard double counting argument) sets itself around an arbitrary vertex of the graph, and furthermore the null graph ($n=0$) can vacuously be made to be strongly regular with any parameters you like.

c8214aaa

Diff

@@ -5,6 +5,7 @@ Authors: Alena Gusakov
 -/
 import Mathlib.Combinatorics.SimpleGraph.Basic
 import Mathlib.Data.Set.Finite
+import Mathlib.Combinatorics.DoubleCounting
 
 #align_import combinatorics.simple_graph.strongly_regular from "leanprover-community/mathlib"@"2b35fc7bea4640cb75e477e83f32fbd538920822"
 
@@ -21,8 +22,6 @@ import Mathlib.Data.Set.Finite
   * The number of common neighbors between any two nonadjacent vertices in `G` is `μ`
 
 ## TODO
-- Prove that the parameters of a strongly regular graph
-  obey the relation `(n - k - 1) * μ = k * (k - ℓ - 1)`
 - Prove that if `I` is the identity matrix and `J` is the all-one matrix,
   then the adj matrix `A` of SRG obeys relation `A^2 = kI + ℓA + μ(J - I - A)`
 -/
@@ -139,7 +138,7 @@ set_option linter.uppercaseLean3 false in
 #align simple_graph.is_SRG_with.compl_is_regular SimpleGraph.IsSRGWith.compl_is_regular
 
 theorem IsSRGWith.card_commonNeighbors_eq_of_adj_compl (h : G.IsSRGWith n k ℓ μ) {v w : V}
-    (ha : Gᶜ.Adj v w) : Fintype.card (↥(Gᶜ.commonNeighbors v w)) = n - (2 * k - μ) - 2 := by
+    (ha : Gᶜ.Adj v w) : Fintype.card (Gᶜ.commonNeighbors v w) = n - (2 * k - μ) - 2 := by
   simp only [← Set.toFinset_card, commonNeighbors, Set.toFinset_inter, neighborSet_compl,
     Set.toFinset_diff, Set.toFinset_singleton, Set.toFinset_compl, ← neighborFinset_def]
   simp_rw [compl_neighborFinset_sdiff_inter_eq]
@@ -156,7 +155,7 @@ set_option linter.uppercaseLean3 false in
 
 theorem IsSRGWith.card_commonNeighbors_eq_of_not_adj_compl (h : G.IsSRGWith n k ℓ μ) {v w : V}
     (hn : v ≠ w) (hna : ¬Gᶜ.Adj v w) :
-    Fintype.card (↥Gᶜ.commonNeighbors v w) = n - (2 * k - ℓ) := by
+    Fintype.card (Gᶜ.commonNeighbors v w) = n - (2 * k - ℓ) := by
   simp only [← Set.toFinset_card, commonNeighbors, Set.toFinset_inter, neighborSet_compl,
     Set.toFinset_diff, Set.toFinset_singleton, Set.toFinset_compl, ← neighborFinset_def]
   simp only [not_and, Classical.not_not, compl_adj] at hna
@@ -176,4 +175,35 @@ theorem IsSRGWith.compl (h : G.IsSRGWith n k ℓ μ) :
 set_option linter.uppercaseLean3 false in
 #align simple_graph.is_SRG_with.compl SimpleGraph.IsSRGWith.compl
 
+/-- The parameters of a strongly regular graph with at least one vertex satisfy
+`k * (k - ℓ - 1) = (n - k - 1) * μ`. -/
+theorem IsSRGWith.param_eq (h : G.IsSRGWith n k ℓ μ) (hn : 0 < n) :
+    k * (k - ℓ - 1) = (n - k - 1) * μ := by
+  rw [← h.card, Fintype.card_pos_iff] at hn
+  obtain ⟨v⟩ := hn
+  convert card_mul_eq_card_mul G.Adj (s := G.neighborFinset v) (t := Gᶜ.neighborFinset v) _ _
+  · simp [h.regular v]
+  · simp [h.compl.regular v]
+  · intro w hw
+    rw [mem_neighborFinset] at hw
+    simp_rw [bipartiteAbove, show G.Adj w = fun a => G.Adj w a by rfl, ← mem_neighborFinset,
+      filter_mem_eq_inter]
+    have s : {v} ⊆ G.neighborFinset w \ G.neighborFinset v := by
+      rw [singleton_subset_iff, mem_sdiff, mem_neighborFinset]
+      exact ⟨hw.symm, G.not_mem_neighborFinset_self v⟩
+    rw [inter_comm, neighborFinset_compl, inter_sdiff, ← sdiff_eq_inter_compl, card_sdiff s,
+      card_singleton, ← sdiff_inter_self_left, card_sdiff (by apply inter_subset_left)]
+    congr
+    · simp [h.regular w]
+    · simp_rw [inter_comm, neighborFinset_def, ← Set.toFinset_inter, ← h.of_adj v w hw,
+        ← Set.toFinset_card]
+      congr!
+  · intro w hw
+    simp_rw [neighborFinset_compl, mem_sdiff, mem_compl, mem_singleton, mem_neighborFinset,
+      ← Ne.def] at hw
+    simp_rw [bipartiteBelow, adj_comm, ← mem_neighborFinset, filter_mem_eq_inter,
+      neighborFinset_def, ← Set.toFinset_inter, ← h.of_not_adj v w hw.2.symm hw.1,
+      ← Set.toFinset_card]
+    congr!
+
 end SimpleGraph

2b35fc7b

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) 2021 Alena Gusakov. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Alena Gusakov
-
-! This file was ported from Lean 3 source module combinatorics.simple_graph.strongly_regular
-! leanprover-community/mathlib commit 2b35fc7bea4640cb75e477e83f32fbd538920822
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathlib.Combinatorics.SimpleGraph.Basic
 import Mathlib.Data.Set.Finite
 
+#align_import combinatorics.simple_graph.strongly_regular from "leanprover-community/mathlib"@"2b35fc7bea4640cb75e477e83f32fbd538920822"
+
 /-!
 # Strongly regular graphs

2b35fc7b

fix: change compl precedence (#5586)

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

4d4f0f25

Diff

@@ -115,16 +115,16 @@ set_option linter.uppercaseLean3 false in
 #align simple_graph.is_SRG_with.card_neighbor_finset_union_of_adj SimpleGraph.IsSRGWith.card_neighborFinset_union_of_adj
 
 theorem compl_neighborFinset_sdiff_inter_eq {v w : V} :
-    G.neighborFinset vᶜ \ {v} ∩ (G.neighborFinset wᶜ \ {w}) =
-      (G.neighborFinset vᶜ ∩ G.neighborFinset wᶜ) \ ({w} ∪ {v}) := by
+    (G.neighborFinset v)ᶜ \ {v} ∩ ((G.neighborFinset w)ᶜ \ {w}) =
+      ((G.neighborFinset v)ᶜ ∩ (G.neighborFinset w)ᶜ) \ ({w} ∪ {v}) := by
   ext
   rw [← not_iff_not]
   simp [imp_iff_not_or, or_assoc, or_comm, or_left_comm]
 #align simple_graph.compl_neighbor_finset_sdiff_inter_eq SimpleGraph.compl_neighborFinset_sdiff_inter_eq
 
 theorem sdiff_compl_neighborFinset_inter_eq {v w : V} (h : G.Adj v w) :
-    (G.neighborFinset vᶜ ∩ G.neighborFinset wᶜ) \ ({w} ∪ {v}) =
-      G.neighborFinset vᶜ ∩ G.neighborFinset wᶜ := by
+    ((G.neighborFinset v)ᶜ ∩ (G.neighborFinset w)ᶜ) \ ({w} ∪ {v}) =
+      (G.neighborFinset v)ᶜ ∩ (G.neighborFinset w)ᶜ := by
   ext
   simp only [and_imp, mem_union, mem_sdiff, mem_compl, and_iff_left_iff_imp, mem_neighborFinset,
     mem_inter, mem_singleton]

2b35fc7b

feat: Port Combinatorics.SimpleGraph.StronglyRegular (#2476)

Co-authored-by: Kyle Miller <kmill31415@gmail.com> Co-authored-by: ChrisHughes24 <chrishughes24@gmail.com>

421d77e2

`combinatorics.simple_graph.strongly_regular` ⟷ `Mathlib.Combinatorics.SimpleGraph.StronglyRegular`

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

PR contents

Lean PRs involved in this bump

leanprover/lean4#2778

leanprover/lean4#2722

leanprover/lean4#2783

Dependencies 6 + 216

combinatorics.simple_graph.strongly_regular ⟷ Mathlib.Combinatorics.SimpleGraph.StronglyRegular

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

PR contents

Lean PRs involved in this bump

leanprover/lean4#2778

leanprover/lean4#2722

leanprover/lean4#2783

Dependencies 6 + 216

`combinatorics.simple_graph.strongly_regular` ⟷ `Mathlib.Combinatorics.SimpleGraph.StronglyRegular`