mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Combinatorics.SimpleGraph.Subgraph

Goal state before:
pp: case verts
V : Type u
G : SimpleGraph V
G' : G.Subgraph
s : Set (Sym2 V)
x✝ : V
⊢ x✝ ∈ (G'.deleteEdges (s ∩ G'.edgeSet)).verts ↔ x✝ ∈ (G'.deleteEdges s).verts

Tactic:
simp +contextual [imp_false]

Goal state after:
Module: Mathlib.Combinatorics.SimpleGraph.Subgraph

Goal state before:
pp: case Adj
V : Type u
G : SimpleGraph V
G' : G.Subgraph
s : Set (Sym2 V)
x✝¹ x✝ : V
⊢ (G'.deleteEdges (s ∩ G'.edgeSet)).Adj x✝¹ x✝ ↔ (G'.deleteEdges s).Adj x✝¹ x✝

Tactic:
simp +contextual [imp_false]

Goal state after:
Module: Mathlib.Combinatorics.SimpleGraph.Walk.Operations

Goal state before:
pp: case cons.nil
V : Type u
G : SimpleGraph V
u v v' w : V
h' : G.Adj v' w
v✝ w✝ : V
p✝ : G.Walk v✝ w✝
ih : ∀ {h : G.Adj w✝ w} {p' : G.Walk v✝ v'}, p✝.concat h = p'.concat h' → ∃ (hv : w✝ = v'), p✝.copy ⋯ hv = p'
h : G.Adj w✝ w
h✝ : G.Adj v' v✝
he : cons h✝ (p✝.concat h) = nil.concat h'
⊢ ∃ (hv : w✝ = v'), (cons h✝ p✝).copy ⋯ hv = nil

pp: case cons.cons
V : Type u
G : SimpleGraph V
u v v' w : V
h' : G.Adj v' w
u✝ v✝¹ w✝ : V
h✝¹ : G.Adj u✝ v✝¹
p✝¹ : G.Walk v✝¹ w✝
ih : ∀ {h : G.Adj w✝ w} {p' : G.Walk v✝¹ v'}, p✝¹.concat h = p'.concat h' → ∃ (hv : w✝ = v'), p✝¹.copy ⋯ hv = p'
h : G.Adj w✝ w
v✝ : V
h✝ : G.Adj u✝ v✝
p✝ : G.Walk v✝ v'
he : cons h✝¹ (p✝¹.concat h) = (cons h✝ p✝).concat h'
⊢ ∃ (hv : w✝ = v'), (cons h✝¹ p✝¹).copy ⋯ hv = cons h✝ p✝

Tactic:
· simp only [concat_nil, cons.injEq] at he
      obtain ⟨rfl, he⟩ := he
      exact (concat_ne_nil _ _ (heq_iff_eq.mp he)).elim

Goal state after:
case cons.cons
V : Type u
G : SimpleGraph V
u v v' w : V
h' : G.Adj v' w
u✝ v✝¹ w✝ : V
h✝¹ : G.Adj u✝ v✝¹
p✝¹ : G.Walk v✝¹ w✝
ih : ∀ {h : G.Adj w✝ w} {p' : G.Walk v✝¹ v'}, p✝¹.concat h = p'.concat h' → ∃ (hv : w✝ = v'), p✝¹.copy ⋯ hv = p'
h : G.Adj w✝ w
v✝ : V
h✝ : G.Adj u✝ v✝
p✝ : G.Walk v✝ v'
he : cons h✝¹ (p✝¹.concat h) = (cons h✝ p✝).concat h'
⊢ ∃ (hv : w✝ = v'), (cons h✝¹ p✝¹).copy ⋯ hv = cons h✝ p✝
Module: Mathlib.Combinatorics.SimpleGraph.Walk.Decomp

Goal state before:
pp: case neg
V : Type u
G : SimpleGraph V
v w u : V
inst✝ : DecidableEq V
a v✝ w✝ : V
h✝ : G.Adj a v✝
p : G.Walk v✝ w✝
ih : ∀ (h : w ∈ p.support), (p.dropUntil w h).support = ((p.drop (List.idxOf w p.support)).copy ⋯ ⋯).support
h : w ∈ (cons h✝ p).support
h' : w ≠ a
⊢ ((cons h✝ p).dropUntil w h).support = (((cons h✝ p).drop (List.idxOf w (cons h✝ p).support)).copy ⋯ ⋯).support

Tactic:
rw [drop_cons_eq _ _ _ (by grind), support_copy, dropUntil]
      grind

Goal state after:
Module: Mathlib.Combinatorics.SimpleGraph.Walk.Decomp

Goal state before:
pp: V : Type u
G : SimpleGraph V
v w u : V
inst✝ : DecidableEq V
p : G.Walk u v
h : w ∈ p.support
⊢ p.dropUntil w h = (p.drop (List.idxOf w p.support)).copy ⋯ ⋯

Tactic:
by
  apply ext_support
  induction p with
  | nil =>
    simp only [dropUntil, eq_mpr_eq_cast, support_nil, getVert_nil, drop, support_copy]
    grind [mem_support_nil_iff, support_nil]
  | @cons a _ _ _ p ih =>
    by_cases! h' : w = a
    · subst h'
      simp [dropUntil_first]
    · rw [drop_cons_eq _ _ _ (by grind), support_copy, dropUntil]
      grind

Goal state after:
Module: Mathlib.Combinatorics.SimpleGraph.Walk.Decomp

Goal state before:
pp: V : Type u
G : SimpleGraph V
w : V
inst✝ : DecidableEq V
u v : V
n : ℕ
p : G.Walk u v
hw : w ∈ p.support
hn : n ≤ (p.takeUntil w hw).length
⊢ (p.takeUntil w hw).getVert n = p.getVert n

Tactic:
by
  conv_rhs => rw [← take_spec p hw, getVert_append]
  cases hn.lt_or_eq <;> simp_all

Goal state after:
Module: Mathlib.Combinatorics.SimpleGraph.Regularity.Chunk

Goal state before:
pp: case refine_1
α : Type u_1
inst✝³ : Fintype α
inst✝² : DecidableEq α
P : Finpartition univ
hP : P.IsEquipartition
G : SimpleGraph α
inst✝¹ : DecidableRel G.Adj
ε : ℝ
U V : Finset α
inst✝ : Nonempty α
hPα : #P.parts * 16 ^ #P.parts ≤ Fintype.card α
hPε : 100 ≤ 4 ^ #P.parts * ε ^ 5
hU : U ∈ P.parts
hV : V ∈ P.parts
A B : Finset (Finset α)
hA : A ⊆ (chunk hP G ε hU).parts
hB : B ⊆ (chunk hP G ε hV).parts
this :
  ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) - ε ^ 5 / 50 ≤
    (1 - ε ^ 5 / 50) * ↑(G.edgeDensity (A.biUnion id) (B.biUnion id))
x y : Finset α
hx : x ∈ A
hy : y ∈ B
⊢ 0 < #A

Tactic:
Finset.card_pos

Goal state after:
case refine_1
α : Type u_1
inst✝³ : Fintype α
inst✝² : DecidableEq α
P : Finpartition univ
hP : P.IsEquipartition
G : SimpleGraph α
inst✝¹ : DecidableRel G.Adj
ε : ℝ
U V : Finset α
inst✝ : Nonempty α
hPα : #P.parts * 16 ^ #P.parts ≤ Fintype.card α
hPε : 100 ≤ 4 ^ #P.parts * ε ^ 5
hU : U ∈ P.parts
hV : V ∈ P.parts
A B : Finset (Finset α)
hA : A ⊆ (chunk hP G ε hU).parts
hB : B ⊆ (chunk hP G ε hV).parts
this :
  ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) - ε ^ 5 / 50 ≤
    (1 - ε ^ 5 / 50) * ↑(G.edgeDensity (A.biUnion id) (B.biUnion id))
x y : Finset α
hx : x ∈ A
hy : y ∈ B
⊢ A.Nonempty
Module: Mathlib.Combinatorics.SimpleGraph.Regularity.Chunk

Goal state before:
pp: case refine_2
α : Type u_1
inst✝³ : Fintype α
inst✝² : DecidableEq α
P : Finpartition univ
hP : P.IsEquipartition
G : SimpleGraph α
inst✝¹ : DecidableRel G.Adj
ε : ℝ
U V : Finset α
inst✝ : Nonempty α
hPα : #P.parts * 16 ^ #P.parts ≤ Fintype.card α
hPε : 100 ≤ 4 ^ #P.parts * ε ^ 5
hU : U ∈ P.parts
hV : V ∈ P.parts
A B : Finset (Finset α)
hA : A ⊆ (chunk hP G ε hU).parts
hB : B ⊆ (chunk hP G ε hV).parts
this :
  ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) - ε ^ 5 / 50 ≤
    (1 - ε ^ 5 / 50) * ↑(G.edgeDensity (A.biUnion id) (B.biUnion id))
x y : Finset α
hx : x ∈ A
hy : y ∈ B
⊢ 0 < #x

Tactic:
Finset.card_pos

Goal state after:
case refine_2
α : Type u_1
inst✝³ : Fintype α
inst✝² : DecidableEq α
P : Finpartition univ
hP : P.IsEquipartition
G : SimpleGraph α
inst✝¹ : DecidableRel G.Adj
ε : ℝ
U V : Finset α
inst✝ : Nonempty α
hPα : #P.parts * 16 ^ #P.parts ≤ Fintype.card α
hPε : 100 ≤ 4 ^ #P.parts * ε ^ 5
hU : U ∈ P.parts
hV : V ∈ P.parts
A B : Finset (Finset α)
hA : A ⊆ (chunk hP G ε hU).parts
hB : B ⊆ (chunk hP G ε hV).parts
this :
  ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) - ε ^ 5 / 50 ≤
    (1 - ε ^ 5 / 50) * ↑(G.edgeDensity (A.biUnion id) (B.biUnion id))
x y : Finset α
hx : x ∈ A
hy : y ∈ B
⊢ x.Nonempty
Module: Mathlib.Combinatorics.SimpleGraph.Regularity.Chunk

Goal state before:
pp: case refine_3
α : Type u_1
inst✝³ : Fintype α
inst✝² : DecidableEq α
P : Finpartition univ
hP : P.IsEquipartition
G : SimpleGraph α
inst✝¹ : DecidableRel G.Adj
ε : ℝ
U V : Finset α
inst✝ : Nonempty α
hPα : #P.parts * 16 ^ #P.parts ≤ Fintype.card α
hPε : 100 ≤ 4 ^ #P.parts * ε ^ 5
hU : U ∈ P.parts
hV : V ∈ P.parts
A B : Finset (Finset α)
hA : A ⊆ (chunk hP G ε hU).parts
hB : B ⊆ (chunk hP G ε hV).parts
this :
  ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) - ε ^ 5 / 50 ≤
    (1 - ε ^ 5 / 50) * ↑(G.edgeDensity (A.biUnion id) (B.biUnion id))
x y : Finset α
hx : x ∈ A
hy : y ∈ B
⊢ 0 < #B

Tactic:
Finset.card_pos

Goal state after:
case refine_3
α : Type u_1
inst✝³ : Fintype α
inst✝² : DecidableEq α
P : Finpartition univ
hP : P.IsEquipartition
G : SimpleGraph α
inst✝¹ : DecidableRel G.Adj
ε : ℝ
U V : Finset α
inst✝ : Nonempty α
hPα : #P.parts * 16 ^ #P.parts ≤ Fintype.card α
hPε : 100 ≤ 4 ^ #P.parts * ε ^ 5
hU : U ∈ P.parts
hV : V ∈ P.parts
A B : Finset (Finset α)
hA : A ⊆ (chunk hP G ε hU).parts
hB : B ⊆ (chunk hP G ε hV).parts
this :
  ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) - ε ^ 5 / 50 ≤
    (1 - ε ^ 5 / 50) * ↑(G.edgeDensity (A.biUnion id) (B.biUnion id))
x y : Finset α
hx : x ∈ A
hy : y ∈ B
⊢ B.Nonempty
Module: Mathlib.Combinatorics.SimpleGraph.Regularity.Chunk

Goal state before:
pp: case refine_4
α : Type u_1
inst✝³ : Fintype α
inst✝² : DecidableEq α
P : Finpartition univ
hP : P.IsEquipartition
G : SimpleGraph α
inst✝¹ : DecidableRel G.Adj
ε : ℝ
U V : Finset α
inst✝ : Nonempty α
hPα : #P.parts * 16 ^ #P.parts ≤ Fintype.card α
hPε : 100 ≤ 4 ^ #P.parts * ε ^ 5
hU : U ∈ P.parts
hV : V ∈ P.parts
A B : Finset (Finset α)
hA : A ⊆ (chunk hP G ε hU).parts
hB : B ⊆ (chunk hP G ε hV).parts
this :
  ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) - ε ^ 5 / 50 ≤
    (1 - ε ^ 5 / 50) * ↑(G.edgeDensity (A.biUnion id) (B.biUnion id))
x y : Finset α
hx : x ∈ A
hy : y ∈ B
⊢ 0 < #y

Tactic:
Finset.card_pos

Goal state after:
case refine_4
α : Type u_1
inst✝³ : Fintype α
inst✝² : DecidableEq α
P : Finpartition univ
hP : P.IsEquipartition
G : SimpleGraph α
inst✝¹ : DecidableRel G.Adj
ε : ℝ
U V : Finset α
inst✝ : Nonempty α
hPα : #P.parts * 16 ^ #P.parts ≤ Fintype.card α
hPε : 100 ≤ 4 ^ #P.parts * ε ^ 5
hU : U ∈ P.parts
hV : V ∈ P.parts
A B : Finset (Finset α)
hA : A ⊆ (chunk hP G ε hU).parts
hB : B ⊆ (chunk hP G ε hV).parts
this :
  ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) - ε ^ 5 / 50 ≤
    (1 - ε ^ 5 / 50) * ↑(G.edgeDensity (A.biUnion id) (B.biUnion id))
x y : Finset α
hx : x ∈ A
hy : y ∈ B
⊢ y.Nonempty
Module: Mathlib.Combinatorics.SimpleGraph.Walk.Operations

Goal state before:
pp: V : Type u
G : SimpleGraph V
u v : V
p : G.Walk u v
⊢ p.dropLast.length = p.length - 1

Tactic:
cases p <;> simp [← length_dropLast_add_one not_nil_cons]

Goal state after:
Module: Mathlib.Combinatorics.SimpleGraph.Clique

Goal state before:
pp: case mp
α : Type u_1
β : Type u_2
G : SimpleGraph α
f : α ↪ β
t : Finset β
ht : t.Nontrivial
s : Finset α
hs : G.IsClique ↑s
hst : ⇑f '' ↑s = ↑t
⊢ ∃ s, G.IsClique ↑s ∧ map f s = t

Tactic:
exact ⟨s,hs, Finset.coe_inj.1 (by simpa)⟩

Goal state after:
Module: Mathlib.Combinatorics.SimpleGraph.Clique

Goal state before:
pp: case card_eq
α : Type u_1
G : SimpleGraph α
n : ℕ
s : Finset α
a : α
inst✝ : DecidableEq α
hs : G.IsNClique n s
h : ∀ b ∈ s, G.Adj a b
⊢ #(insert a s) = n + 1

Tactic:
card_insert_of_notMem fun ha => (h _ ha).ne rfl,

Goal state after:
case card_eq
α : Type u_1
G : SimpleGraph α
n : ℕ
s : Finset α
a : α
inst✝ : DecidableEq α
hs : G.IsNClique n s
h : ∀ b ∈ s, G.Adj a b
⊢ #s + 1 = n + 1
Module: Mathlib.Combinatorics.SimpleGraph.Paths

Goal state before:
pp: V : Type u
G : SimpleGraph V
u v : V
p q : G.Walk u v
hp : p.IsPath
hq : q.IsPath
h : p ≠ q
⊢ ∃ u' v' p' q', p'.IsSubwalk p ∧ q'.IsSubwalk q ∧ (p'.append q'.reverse).IsCycle

Tactic:
induction hs : p.length using Nat.strongRec generalizing u v with | ind s ih =>
  by_cases! hw : ∃ w, w ∈ p.support ∧ w ∈ q.support ∧ w ≠ u ∧ w ≠ v
  · classical
    have ⟨w, hwp, hwq, hwu, hwv⟩ := hw
    by_cases! p.takeUntil w hwp ≠ q.takeUntil w hwq
    · have := ih _ (hs ▸ length_takeUntil_lt_length hwp hwv) (hp.takeUntil hwp) (hq.takeUntil hwq)
      grind [isSubwalk_takeUntil, IsSubwalk.trans]
    · have := ih _ (hs ▸ length_dropUntil_lt_length hwp hwu) (hp.dropUntil hwp) (hq.dropUntil hwq)
        <| by grind [take_spec]
      grind [isSubwalk_dropUntil, IsSubwalk.trans]
  · refine ⟨u, v, p, q, p.isSubwalk_rfl, q.isSubwalk_rfl, ?_⟩
    refine hp.isCycle_append (isPath_reverse_iff q |>.mpr hq) (fun _ ↦ ?_) ?_
    · grind [dropLast_support_concat, IsPath.support_nodup, support_reverse, cons_tail_support]
    · grind [length_reverse, eq_of_length_le_one]

Goal state after:
Module: Mathlib.Combinatorics.SimpleGraph.Clique

Goal state before:
pp: α : Type u_1
G : SimpleGraph α
s : Set α
⊢ (∀ ⦃x : α⦄, x ∈ s → ∀ ⦃y : α⦄, y ∈ s → x ≠ y → Gᶜ.Adj x y) ↔ ∀ ⦃x : α⦄, x ∈ s → ∀ ⦃y : α⦄, y ∈ s → x ≠ y → ¬G.Adj x y

Tactic:
simp_all [compl_adj]

Goal state after:
Module: Mathlib.Combinatorics.SimpleGraph.Regularity.Chunk

Goal state before:
pp: case refine_1
α : Type u_1
inst✝³ : Fintype α
inst✝² : DecidableEq α
P : Finpartition univ
hP : P.IsEquipartition
G : SimpleGraph α
inst✝¹ : DecidableRel G.Adj
ε : ℝ
U V : Finset α
inst✝ : Nonempty α
hPα : #P.parts * 16 ^ #P.parts ≤ Fintype.card α
hPε : 100 ≤ 4 ^ #P.parts * ε ^ 5
hε₁ : ε ≤ 1
hU : U ∈ P.parts
hV : V ∈ P.parts
A B : Finset (Finset α)
hA : A ⊆ (chunk hP G ε hU).parts
hB : B ⊆ (chunk hP G ε hV).parts
this :
  (1 + ε ^ 5 / 49) * ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) ≤
    ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) + ε ^ 5 / 49
x y : Finset α
hx : x ∈ A
hy : y ∈ B
⊢ 0 < #A

Tactic:
Finset.card_pos

Goal state after:
case refine_1
α : Type u_1
inst✝³ : Fintype α
inst✝² : DecidableEq α
P : Finpartition univ
hP : P.IsEquipartition
G : SimpleGraph α
inst✝¹ : DecidableRel G.Adj
ε : ℝ
U V : Finset α
inst✝ : Nonempty α
hPα : #P.parts * 16 ^ #P.parts ≤ Fintype.card α
hPε : 100 ≤ 4 ^ #P.parts * ε ^ 5
hε₁ : ε ≤ 1
hU : U ∈ P.parts
hV : V ∈ P.parts
A B : Finset (Finset α)
hA : A ⊆ (chunk hP G ε hU).parts
hB : B ⊆ (chunk hP G ε hV).parts
this :
  (1 + ε ^ 5 / 49) * ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) ≤
    ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) + ε ^ 5 / 49
x y : Finset α
hx : x ∈ A
hy : y ∈ B
⊢ A.Nonempty
Module: Mathlib.Combinatorics.SimpleGraph.Clique

Goal state before:
pp: α : Type u_1
G : SimpleGraph α
s : Set α
⊢ (∀ ⦃x : α⦄, x ∈ s → ∀ ⦃y : α⦄, y ∈ s → x ≠ y → ¬Gᶜ.Adj x y) ↔ ∀ ⦃x : α⦄, x ∈ s → ∀ ⦃y : α⦄, y ∈ s → x ≠ y → G.Adj x y

Tactic:
simp_all [compl_adj]

Goal state after:
Module: Mathlib.Combinatorics.SimpleGraph.Regularity.Chunk

Goal state before:
pp: case refine_2
α : Type u_1
inst✝³ : Fintype α
inst✝² : DecidableEq α
P : Finpartition univ
hP : P.IsEquipartition
G : SimpleGraph α
inst✝¹ : DecidableRel G.Adj
ε : ℝ
U V : Finset α
inst✝ : Nonempty α
hPα : #P.parts * 16 ^ #P.parts ≤ Fintype.card α
hPε : 100 ≤ 4 ^ #P.parts * ε ^ 5
hε₁ : ε ≤ 1
hU : U ∈ P.parts
hV : V ∈ P.parts
A B : Finset (Finset α)
hA : A ⊆ (chunk hP G ε hU).parts
hB : B ⊆ (chunk hP G ε hV).parts
this :
  (1 + ε ^ 5 / 49) * ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) ≤
    ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) + ε ^ 5 / 49
x y : Finset α
hx : x ∈ A
hy : y ∈ B
⊢ 0 < #x

Tactic:
Finset.card_pos

Goal state after:
case refine_2
α : Type u_1
inst✝³ : Fintype α
inst✝² : DecidableEq α
P : Finpartition univ
hP : P.IsEquipartition
G : SimpleGraph α
inst✝¹ : DecidableRel G.Adj
ε : ℝ
U V : Finset α
inst✝ : Nonempty α
hPα : #P.parts * 16 ^ #P.parts ≤ Fintype.card α
hPε : 100 ≤ 4 ^ #P.parts * ε ^ 5
hε₁ : ε ≤ 1
hU : U ∈ P.parts
hV : V ∈ P.parts
A B : Finset (Finset α)
hA : A ⊆ (chunk hP G ε hU).parts
hB : B ⊆ (chunk hP G ε hV).parts
this :
  (1 + ε ^ 5 / 49) * ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) ≤
    ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) + ε ^ 5 / 49
x y : Finset α
hx : x ∈ A
hy : y ∈ B
⊢ x.Nonempty
Module: Mathlib.Combinatorics.SimpleGraph.Regularity.Chunk

Goal state before:
pp: case refine_3
α : Type u_1
inst✝³ : Fintype α
inst✝² : DecidableEq α
P : Finpartition univ
hP : P.IsEquipartition
G : SimpleGraph α
inst✝¹ : DecidableRel G.Adj
ε : ℝ
U V : Finset α
inst✝ : Nonempty α
hPα : #P.parts * 16 ^ #P.parts ≤ Fintype.card α
hPε : 100 ≤ 4 ^ #P.parts * ε ^ 5
hε₁ : ε ≤ 1
hU : U ∈ P.parts
hV : V ∈ P.parts
A B : Finset (Finset α)
hA : A ⊆ (chunk hP G ε hU).parts
hB : B ⊆ (chunk hP G ε hV).parts
this :
  (1 + ε ^ 5 / 49) * ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) ≤
    ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) + ε ^ 5 / 49
x y : Finset α
hx : x ∈ A
hy : y ∈ B
⊢ 0 < #B

Tactic:
Finset.card_pos

Goal state after:
case refine_3
α : Type u_1
inst✝³ : Fintype α
inst✝² : DecidableEq α
P : Finpartition univ
hP : P.IsEquipartition
G : SimpleGraph α
inst✝¹ : DecidableRel G.Adj
ε : ℝ
U V : Finset α
inst✝ : Nonempty α
hPα : #P.parts * 16 ^ #P.parts ≤ Fintype.card α
hPε : 100 ≤ 4 ^ #P.parts * ε ^ 5
hε₁ : ε ≤ 1
hU : U ∈ P.parts
hV : V ∈ P.parts
A B : Finset (Finset α)
hA : A ⊆ (chunk hP G ε hU).parts
hB : B ⊆ (chunk hP G ε hV).parts
this :
  (1 + ε ^ 5 / 49) * ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) ≤
    ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) + ε ^ 5 / 49
x y : Finset α
hx : x ∈ A
hy : y ∈ B
⊢ B.Nonempty
Module: Mathlib.Combinatorics.SimpleGraph.Clique

Goal state before:
pp: α : Type u_3
G : SimpleGraph α
inst✝ : Finite α
t : Finset α
tc : G.IsIndepSet ↑t
⊢ #t ≤ G.indepNum

Tactic:
rw [← isClique_compl] at tc
  simp_rw [indepNum, ← isNClique_compl]
  exact tc.card_le_cliqueNum

Goal state after:
Module: Mathlib.Combinatorics.SimpleGraph.Regularity.Chunk

Goal state before:
pp: case refine_4
α : Type u_1
inst✝³ : Fintype α
inst✝² : DecidableEq α
P : Finpartition univ
hP : P.IsEquipartition
G : SimpleGraph α
inst✝¹ : DecidableRel G.Adj
ε : ℝ
U V : Finset α
inst✝ : Nonempty α
hPα : #P.parts * 16 ^ #P.parts ≤ Fintype.card α
hPε : 100 ≤ 4 ^ #P.parts * ε ^ 5
hε₁ : ε ≤ 1
hU : U ∈ P.parts
hV : V ∈ P.parts
A B : Finset (Finset α)
hA : A ⊆ (chunk hP G ε hU).parts
hB : B ⊆ (chunk hP G ε hV).parts
this :
  (1 + ε ^ 5 / 49) * ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) ≤
    ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) + ε ^ 5 / 49
x y : Finset α
hx : x ∈ A
hy : y ∈ B
⊢ 0 < #y

Tactic:
Finset.card_pos

Goal state after:
case refine_4
α : Type u_1
inst✝³ : Fintype α
inst✝² : DecidableEq α
P : Finpartition univ
hP : P.IsEquipartition
G : SimpleGraph α
inst✝¹ : DecidableRel G.Adj
ε : ℝ
U V : Finset α
inst✝ : Nonempty α
hPα : #P.parts * 16 ^ #P.parts ≤ Fintype.card α
hPε : 100 ≤ 4 ^ #P.parts * ε ^ 5
hε₁ : ε ≤ 1
hU : U ∈ P.parts
hV : V ∈ P.parts
A B : Finset (Finset α)
hA : A ⊆ (chunk hP G ε hU).parts
hB : B ⊆ (chunk hP G ε hV).parts
this :
  (1 + ε ^ 5 / 49) * ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) ≤
    ↑(G.edgeDensity (A.biUnion id) (B.biUnion id)) + ε ^ 5 / 49
x y : Finset α
hx : x ∈ A
hy : y ∈ B
⊢ y.Nonempty
Module: Mathlib.Combinatorics.SimpleGraph.Regularity.Chunk

Goal state before:
pp: case hab.refine_2
α : Type u_1
inst✝³ : Fintype α
inst✝² : DecidableEq α
P : Finpartition univ
G : SimpleGraph α
inst✝¹ : DecidableRel G.Adj
ε : ℝ
U V : Finset α
inst✝ : Nonempty α
hP : P.IsEquipartition
hPα : #P.parts * 16 ^ #P.parts ≤ Fintype.card α
hPε : 100 ≤ 4 ^ #P.parts * ε ^ 5
hU : U ∈ P.parts
hV : V ∈ P.parts
hGε : 0 ≤ ↑(G.edgeDensity U V) - ε ^ 5 / 50
this : 0 ≤ ε
rflU : (chunk hP G ε hU).parts ⊆ (chunk hP G ε hU).parts
rflV : (chunk hP G ε hV).parts ⊆ (chunk hP G ε hV).parts
⊢ (∑ ab ∈ (chunk hP G ε hU).parts.product (chunk hP G ε hV).parts, ↑(G.edgeDensity ab.1 ab.2)) /
      (↑(#(chunk hP G ε hU).parts) * ↑(#(chunk hP G ε hV).parts)) ≤
    (∑ ab ∈ (chunk hP G ε hU).parts.product (chunk hP G ε hV).parts, ↑(G.edgeDensity ab.1 ab.2)) / 16 ^ #P.parts

Tactic:
rw [card_chunk (m_pos hPα).ne', card_chunk (m_pos hPα).ne', ← cast_mul, ← mul_pow, cast_pow]
        norm_cast

Goal state after:
Module: Mathlib.Combinatorics.Additive.Dissociation

Goal state before:
pp: α : Type u_1
inst✝² : CommGroup α
inst✝¹ : DecidableEq α
inst✝ : Fintype α
s t u : Finset α
ht : t ⊆ s
hu : u ⊆ s
⊢ ∏ a ∈ s, a ^ ((↑t).indicator 1 - (↑u).indicator 1) a = (∏ a ∈ t, a) / ∏ a ∈ u, a

Tactic:
by simp [prod_div_distrib, zpow_sub,
      ← div_eq_mul_inv, Set.indicator, pow_ite, inter_eq_right.2, *]

Goal state after:
Module: Mathlib.Combinatorics.Additive.DoublingConst

Goal state before:
pp: G : Type u_1
inst✝² : Group G
inst✝¹ : DecidableEq G
A B : Finset G
inst✝ : Fintype G
⊢ σₘ[A, B] ≤ A.dens⁻¹

Tactic:
rw [dens, inv_div, mulConst]

Goal state after:
G : Type u_1
inst✝² : Group G
inst✝¹ : DecidableEq G
A B : Finset G
inst✝ : Fintype G
⊢ ↑(#(A * B)) / ↑(#A) ≤ ↑(Fintype.card G) / ↑(#A)
Module: Mathlib.Combinatorics.Additive.ErdosGinzburgZiv

Goal state before:
pp: case refine_1
ι : Type u_1
p : ℕ
inst✝ : Fact (Nat.Prime p)
s : Finset ι
a : ι → ZMod p
hs : #s = 2 * p - 1
this : NeZero p
N : ℕ := Fintype.card { x // (eval x) (f₁ s a) = 0 ∧ (eval x) (f₂ s a) = 0 }
zero_sol : { x // (eval x) (f₁ s a) = 0 ∧ (eval x) (f₂ s a) = 0 } := ⟨0, ⋯⟩
hN₀ : 0 < N
hs' : 2 * p - 1 = Fintype.card ↥s
hpN : p ∣ N
x : { x // (eval x) (f₁ s a) = 0 ∧ (eval x) (f₂ s a) = 0 }
hx : x ≠ zero_sol
⊢ Finset.map { toFun := Subtype.val, inj' := ⋯ } {a_1 | ↑x a_1 ≠ 0} ⊆ s

Tactic:
simp +contextual [subset_iff]

Goal state after:
Module: Mathlib.FieldTheory.ChevalleyWarning

Goal state before:
pp: K : Type u_1
σ : Type u_2
inst✝⁵ : Fintype K
inst✝⁴ : Field K
inst✝³ : Fintype σ
inst✝² : DecidableEq σ
inst✝¹ : DecidableEq K
p : ℕ
inst✝ : CharP K p
f : MvPolynomial σ K
h : f.totalDegree < Fintype.card σ
F : Unit → MvPolynomial σ K := fun x ↦ f
⊢ p ∣ Fintype.card { x // (eval x) f = 0 }

Tactic:
have : (∑ i : Unit, (F i).totalDegree) < Fintype.card σ := h

Goal state after:
K : Type u_1
σ : Type u_2
inst✝⁵ : Fintype K
inst✝⁴ : Field K
inst✝³ : Fintype σ
inst✝² : DecidableEq σ
inst✝¹ : DecidableEq K
p : ℕ
inst✝ : CharP K p
f : MvPolynomial σ K
h : f.totalDegree < Fintype.card σ
F : Unit → MvPolynomial σ K := fun x ↦ f
this : ∑ i, (F i).totalDegree < Fintype.card σ
⊢ p ∣ Fintype.card { x // (eval x) f = 0 }
Module: Mathlib.Combinatorics.Additive.Randomisation

Goal state before:
pp: G : Type u_1
inst✝¹ : Fintype G
inst✝ : AddCommGroup G
c : AddChar G ℂ → ℝ
d : AddChar G ℂ → ℂ
hcd : AddDissociated {ψ | d ψ ≠ 0}
⊢ 𝔼 a, ∏ ψ, (c ψ + (d ψ * ψ a).re) = ∏ ψ, c ψ

Tactic:
refine Complex.ofReal_injective ?_
  push_cast
  calc
    _ = ∑ t, (𝔼 a, ∏ ψ ∈ t, ((d ψ * ψ a) + conj (d ψ * ψ a)) / 2) * ∏ ψ ∈ tᶜ, (c ψ : ℂ) := by
        simp_rw [expect_mul, ← expect_sum_comm, ← Fintype.prod_add, add_comm,
          Complex.re_eq_add_conj]
    _ = (𝔼 a, ∏ ψ ∈ ∅, ((d ψ * ψ a) + conj (d ψ * ψ a)) / 2) * ∏ ψ ∈ ∅ᶜ, (c ψ : ℂ) :=
        Fintype.sum_eq_single ∅ fun t ht ↦ mul_eq_zero_of_left ?_ _
    _ = ∏ ψ, (c ψ : ℂ) := by simp
  simp only [map_mul, prod_div_distrib, prod_add, prod_const, ← expect_div, expect_sum_comm,
    div_eq_zero_iff, pow_eq_zero_iff', OfNat.ofNat_ne_zero, ne_eq, card_eq_zero,
    false_and, or_false]
  refine sum_eq_zero fun u _ ↦ ?_
  calc
    𝔼 a, (∏ ψ ∈ u, d ψ * ψ a) * ∏ ψ ∈ t \ u, conj (d ψ) * conj (ψ a)
      = ((∏ ψ ∈ u, d ψ) * ∏ ψ ∈ t \ u, conj (d ψ)) * 𝔼 a, (∑ ψ ∈ u, ψ - ∑ ψ ∈ t \ u, ψ) a := by
        simp_rw [mul_expect, AddChar.sub_apply, AddChar.sum_apply, mul_mul_mul_comm,
          ← prod_mul_distrib, AddChar.map_neg_eq_conj]
    _ = 0 := ?_
  rw [mul_eq_zero, AddChar.expect_eq_zero_iff_ne_zero, sub_ne_zero, or_iff_not_imp_left, ← Ne,
    mul_ne_zero_iff, prod_ne_zero_iff, prod_ne_zero_iff]
  exact fun h ↦ hcd.ne h.1 (by simpa only [map_ne_zero] using! h.2)
    (sdiff_ne_right.2 <| .inl ht).symm

Goal state after:
Module: Mathlib.Data.Nat.BitIndices

Goal state before:
pp: case bit
b : Bool
n : ℕ
hs : n.bitIndices.SortedLT
⊢ (bit b n).bitIndices.SortedLT

Tactic:
suffices List.Pairwise (fun a b ↦ a < b) n.bitIndices by
      cases b <;> simpa [sortedLT_iff_pairwise, bit_false, bit_true, List.pairwise_map]
    exact List.Pairwise.imp (by simp) hs.pairwise

Goal state after:
Module: Mathlib.Combinatorics.Compactness

Goal state before:
pp: α : Type u_1
β : α → Type u_2
inst✝ : ∀ (a : α), Finite (β a)
g : (s : Finset α) → (a : ↥s) → β ↑a
⊢ ∃ χ, ∀ (s : Finset α), ∃ t, ∃ (hst : s ⊆ t), ∀ (x : ↥s), χ ↑x = g t (Set.inclusion hst x)

Tactic:
by
  classical
  have (a : α) : Nonempty (β a) := ⟨g {a} ⟨a, by simp⟩⟩
  let g' (s) (a : α) : β a := if ha : a ∈ s then g s ⟨a, ha⟩ else Classical.arbitrary (β a)
  have hg (s : Finset α) (x : s) : g s x = g' s x := by simp [g']
  simpa [hg] using Finset.rado_selection g'

Goal state after:
Module: Mathlib.LinearAlgebra.Projectivization.Constructions

Goal state before:
pp: F : Type u_1
inst✝¹ : Field F
inst✝ : DecidableEq F
v w : Fin 3 → F
hv : v ≠ 0
hw : w ≠ 0
⊢ (mk F v hv).cross (mk F w hw) = if h : (crossProduct v) w = 0 then mk F v hv else mk F ((crossProduct v) w) h

Tactic:
change Quotient.mk'' _ = _
  split_ifs with h <;> simp only [h] <;> rfl

Goal state after:
Module: Mathlib.Combinatorics.Colex

Goal state before:
pp: case refine_2.inl
α : Type u_1
inst✝¹ : LinearOrder α
𝒜 : Finset (Finset α)
r : ℕ
inst✝ : Fintype α
h𝒜 : IsInitSeg 𝒜 r
h𝒜₀ : 𝒜.Nonempty
hs : 𝒜.sup' h𝒜₀ ⇑toColex ∈ ⇑ofColex ⁻¹' ↑𝒜
t : Finset α
cards : #(𝒜.sup' h𝒜₀ ⇑toColex) = #t
le : toColex t ≤ toColex (𝒜.sup' h𝒜₀ ⇑toColex)
p : toColex t = toColex (𝒜.sup' h𝒜₀ ⇑toColex)
⊢ t ∈ 𝒜

pp: case refine_2.inr
α : Type u_1
inst✝¹ : LinearOrder α
𝒜 : Finset (Finset α)
r : ℕ
inst✝ : Fintype α
h𝒜 : IsInitSeg 𝒜 r
h𝒜₀ : 𝒜.Nonempty
hs : 𝒜.sup' h𝒜₀ ⇑toColex ∈ ⇑ofColex ⁻¹' ↑𝒜
t : Finset α
cards : #(𝒜.sup' h𝒜₀ ⇑toColex) = #t
le : toColex t ≤ toColex (𝒜.sup' h𝒜₀ ⇑toColex)
p : toColex t < toColex (𝒜.sup' h𝒜₀ ⇑toColex)
⊢ t ∈ 𝒜

Tactic:
· rwa [toColex_inj.1 p]

Goal state after:
case refine_2.inr
α : Type u_1
inst✝¹ : LinearOrder α
𝒜 : Finset (Finset α)
r : ℕ
inst✝ : Fintype α
h𝒜 : IsInitSeg 𝒜 r
h𝒜₀ : 𝒜.Nonempty
hs : 𝒜.sup' h𝒜₀ ⇑toColex ∈ ⇑ofColex ⁻¹' ↑𝒜
t : Finset α
cards : #(𝒜.sup' h𝒜₀ ⇑toColex) = #t
le : toColex t ≤ toColex (𝒜.sup' h𝒜₀ ⇑toColex)
p : toColex t < toColex (𝒜.sup' h𝒜₀ ⇑toColex)
⊢ t ∈ 𝒜