mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Combinatorics.SetFamily.Compression.UV

Goal state before:
pp: α : Type u_1
inst✝ : DecidableEq α
𝒜 : Finset (Finset α)
u v : Finset α
huv : ∀ x ∈ u, ∃ y ∈ v, IsCompressed (u.erase x) (v.erase y) 𝒜
𝒜' : Finset (Finset α) := 𝓒 u v 𝒜
s : Finset α
hs𝒜' : s ∈ ∂ 𝒜'
hs𝒜 : s ∉ ∂ 𝒜
m : ∀ y ∉ s, insert y s ∉ 𝒜
x : α
left✝ : x ∉ s
right✝ : insert x s ∈ 𝒜'
hus : u ⊆ insert x s
hvs : Disjoint v (insert x s)
this✝¹ : (insert x s ∪ v) \ u ∈ 𝒜
hsv : Disjoint s v
hvu : Disjoint v u
hxv : x ∉ v
this✝ : v \ u = v
hxu : x ∈ u
y : α
hyv : y ∈ v
hxy : IsCompressed (u.erase x) (v.erase y) 𝒜
this : ((insert x s ∪ v) \ u ∪ u.erase x) \ v.erase y ∈ 𝒜
⊢ insert y s = ((insert x s ∪ v) \ u ∪ u.erase x) \ v.erase y

Tactic:
rw [sdiff_union_erase_cancel (hus.trans subset_union_left) ‹x ∈ u›, erase_union_distrib,
      erase_insert ‹x ∉ s›, erase_eq_of_notMem ‹x ∉ v›, sdiff_erase (mem_union_right _ hyv),
      union_sdiff_cancel_right hsv]

Goal state after:
Module: Mathlib.Combinatorics.SetFamily.Compression.UV

Goal state before:
pp: case neg
α : Type u_1
inst✝ : DecidableEq α
𝒜 : Finset (Finset α)
u v : Finset α
huv : ∀ x ∈ u, ∃ y ∈ v, IsCompressed (u.erase x) (v.erase y) 𝒜
𝒜' : Finset (Finset α) := 𝓒 u v 𝒜
s : Finset α
hs𝒜' : s ∈ ∂ 𝒜'
hs𝒜 : s ∉ ∂ 𝒜
m : ∀ y ∉ s, insert y s ∉ 𝒜
x : α
left✝ : x ∉ s
right✝ : insert x s ∈ 𝒜'
hus✝ : u ⊆ insert x s
hvs : Disjoint v (insert x s)
this✝² : (insert x s ∪ v) \ u ∈ 𝒜
hsv : Disjoint s v
hvu : Disjoint v u
hxv : x ∉ v
this✝¹ : v \ u = v
this✝ : x ∉ u
hus : u ⊆ s
w : α
hwB : w ∈ s ∪ v → w ∈ u
hw𝒜' : insert w ((s ∪ v) \ u) ∈ 𝒜'
this : v ⊆ insert w ((s ∪ v) \ u)
hwu : w ∉ u
⊢ False

Tactic:
apply m w (hwu ∘ hwB ∘ mem_union_left _)

Goal state after:
case neg
α : Type u_1
inst✝ : DecidableEq α
𝒜 : Finset (Finset α)
u v : Finset α
huv : ∀ x ∈ u, ∃ y ∈ v, IsCompressed (u.erase x) (v.erase y) 𝒜
𝒜' : Finset (Finset α) := ⋯
s : Finset α
hs𝒜' : s ∈ ∂ 𝒜'
hs𝒜 : s ∉ ∂ 𝒜
m : ∀ y ∉ s, insert y s ∉ 𝒜
x : α
left✝ : x ∉ s
right✝ : insert x s ∈ 𝒜'
hus✝ : u ⊆ insert x s
hvs : Disjoint v (insert x s)
this✝² : (insert x s ∪ v) \ u ∈ 𝒜
hsv : Disjoint s v
hvu : Disjoint v u
hxv : x ∉ v
this✝¹ : v \ u = v
this✝ : x ∉ u
hus : u ⊆ s
w : α
hwB : w ∈ s ∪ v → w ∈ u
hw𝒜' : insert w ((s ∪ v) \ u) ∈ 𝒜'
this : v ⊆ insert w ((s ∪ v) \ u)
hwu : w ∉ u
⊢ insert w s ∈ 𝒜
Module: Mathlib.Combinatorics.SetFamily.FourFunctions

Goal state before:
pp: case neg
α : Type u_1
β : Type u_2
inst✝⁴ : DecidableEq α
inst✝³ : CommSemiring β
inst✝² : LinearOrder β
inst✝¹ : IsStrictOrderedRing β
a : α
f₁ f₂ f₃ f₄ : Finset α → β
u : Finset α
inst✝ : ExistsAddOfLE β
hu : a ∉ u
h₁ : 0 ≤ f₁
h₂ : 0 ≤ f₂
h₃ : 0 ≤ f₃
h₄ : 0 ≤ f₄
h : ∀ ⦃s : Finset α⦄, s ⊆ insert a u → ∀ ⦃t : Finset α⦄, t ⊆ insert a u → f₁ s * f₂ t ≤ f₃ (s ∩ t) * f₄ (s ∪ t)
𝒜 ℬ : Finset (Finset α)
s : Finset α
hsu : s ⊆ u
t : Finset α
htu : t ⊆ u
this✝⁴ : s ⊆ insert a u
this✝³ : t ⊆ insert a u
this✝² : insert a s ⊆ insert a u
this✝¹ : insert a t ⊆ insert a u
has : a ∉ s
hat : a ∉ t
this✝ : a ∉ s ∩ t
this : a ∉ s ∪ t
h✝¹ : s ∈ 𝒜
h✝ : insert a s ∉ 𝒜
⊢ f₁ s * collapse ℬ a f₂ t ≤ collapse (𝒜 ⊼ ℬ) a f₃ (s ∩ t) * collapse (𝒜 ⊻ ℬ) a f₄ (s ∪ t)

Tactic:
collapse_eq hat,

Goal state after:
case neg
α : Type u_1
β : Type u_2
inst✝⁴ : DecidableEq α
inst✝³ : CommSemiring β
inst✝² : LinearOrder β
inst✝¹ : IsStrictOrderedRing β
a : α
f₁ f₂ f₃ f₄ : Finset α → β
u : Finset α
inst✝ : ExistsAddOfLE β
hu : a ∉ u
h₁ : 0 ≤ f₁
h₂ : 0 ≤ f₂
h₃ : 0 ≤ f₃
h₄ : 0 ≤ f₄
h : ∀ ⦃s : Finset α⦄, s ⊆ insert a u → ∀ ⦃t : Finset α⦄, t ⊆ insert a u → f₁ s * f₂ t ≤ f₃ (s ∩ t) * f₄ (s ∪ t)
𝒜 ℬ : Finset (Finset α)
s : Finset α
hsu : s ⊆ u
t : Finset α
htu : t ⊆ u
this✝⁴ : s ⊆ insert a u
this✝³ : t ⊆ insert a u
this✝² : insert a s ⊆ insert a u
this✝¹ : insert a t ⊆ insert a u
has : a ∉ s
hat : a ∉ t
this✝ : a ∉ s ∩ t
this : a ∉ s ∪ t
h✝¹ : s ∈ 𝒜
h✝ : insert a s ∉ 𝒜
⊢ f₁ s * ((if t ∈ ℬ then f₂ t else 0) + if insert a t ∈ ℬ then f₂ (insert a t) else 0) ≤
    collapse (𝒜 ⊼ ℬ) a f₃ (s ∩ t) * collapse (𝒜 ⊻ ℬ) a f₄ (s ∪ t)
Module: Mathlib.Combinatorics.SetFamily.Shatter

Goal state before:
pp: case pos
α : Type u_1
inst✝ : DecidableEq α
𝒜✝ : Finset (Finset α)
a : α
𝒜 : Finset (Finset α)
ih₀ : #(nonMemberSubfamily a 𝒜) ≤ #(nonMemberSubfamily a 𝒜).shatterer
ih₁ : #(memberSubfamily a 𝒜) ≤ #(memberSubfamily a 𝒜).shatterer
ℬ : Finset (Finset α) := image (insert a) ((memberSubfamily a 𝒜).shatterer ∩ (nonMemberSubfamily a 𝒜).shatterer)
hℬ : #ℬ = #((memberSubfamily a 𝒜).shatterer ∩ (nonMemberSubfamily a 𝒜).shatterer)
s t : Finset α
ht : t.erase a ⊆ s
hs : (memberSubfamily a 𝒜).Shatters s ∧ (nonMemberSubfamily a 𝒜).Shatters s
ha : a ∈ t
u : Finset α
hu : insert a u ∈ 𝒜 ∧ a ∉ u
hsu : s ∩ u = t.erase a
⊢ ∃ u ∈ 𝒜, insert a s ∩ u = t

Tactic:
refine ⟨_, hu.1, ?_⟩

Goal state after:
case pos
α : Type u_1
inst✝ : DecidableEq α
𝒜✝ : Finset (Finset α)
a : α
𝒜 : Finset (Finset α)
ih₀ : #(nonMemberSubfamily a 𝒜) ≤ #(nonMemberSubfamily a 𝒜).shatterer
ih₁ : #(memberSubfamily a 𝒜) ≤ #(memberSubfamily a 𝒜).shatterer
ℬ : Finset (Finset α) := image (insert a) ((memberSubfamily a 𝒜).shatterer ∩ (nonMemberSubfamily a 𝒜).shatterer)
hℬ : #ℬ = #((memberSubfamily a 𝒜).shatterer ∩ (nonMemberSubfamily a 𝒜).shatterer)
s t : Finset α
ht : t.erase a ⊆ s
hs : (memberSubfamily a 𝒜).Shatters s ∧ (nonMemberSubfamily a 𝒜).Shatters s
ha : a ∈ t
u : Finset α
hu : insert a u ∈ 𝒜 ∧ a ∉ u
hsu : s ∩ u = t.erase a
⊢ insert a s ∩ insert a u = t
Module: Mathlib.Combinatorics.SetFamily.Shatter

Goal state before:
pp: case neg
α : Type u_1
inst✝ : DecidableEq α
𝒜✝ : Finset (Finset α)
a : α
𝒜 : Finset (Finset α)
ih₀ : #(nonMemberSubfamily a 𝒜) ≤ #(nonMemberSubfamily a 𝒜).shatterer
ih₁ : #(memberSubfamily a 𝒜) ≤ #(memberSubfamily a 𝒜).shatterer
ℬ : Finset (Finset α) := image (insert a) ((memberSubfamily a 𝒜).shatterer ∩ (nonMemberSubfamily a 𝒜).shatterer)
hℬ : #ℬ = #((memberSubfamily a 𝒜).shatterer ∩ (nonMemberSubfamily a 𝒜).shatterer)
s t : Finset α
ht : t.erase a ⊆ s
hs : (memberSubfamily a 𝒜).Shatters s ∧ (nonMemberSubfamily a 𝒜).Shatters s
ha : a ∉ t
u : Finset α
hu : u ∈ 𝒜 ∧ a ∉ u
hsu : s ∩ u = t.erase a
⊢ ∃ u ∈ 𝒜, insert a s ∩ u = t

Tactic:
refine ⟨_, hu.1, ?_⟩

Goal state after:
case neg
α : Type u_1
inst✝ : DecidableEq α
𝒜✝ : Finset (Finset α)
a : α
𝒜 : Finset (Finset α)
ih₀ : #(nonMemberSubfamily a 𝒜) ≤ #(nonMemberSubfamily a 𝒜).shatterer
ih₁ : #(memberSubfamily a 𝒜) ≤ #(memberSubfamily a 𝒜).shatterer
ℬ : Finset (Finset α) := image (insert a) ((memberSubfamily a 𝒜).shatterer ∩ (nonMemberSubfamily a 𝒜).shatterer)
hℬ : #ℬ = #((memberSubfamily a 𝒜).shatterer ∩ (nonMemberSubfamily a 𝒜).shatterer)
s t : Finset α
ht : t.erase a ⊆ s
hs : (memberSubfamily a 𝒜).Shatters s ∧ (nonMemberSubfamily a 𝒜).Shatters s
ha : a ∉ t
u : Finset α
hu : u ∈ 𝒜 ∧ a ∉ u
hsu : s ∩ u = t.erase a
⊢ insert a s ∩ u = t
Module: Mathlib.Combinatorics.SetFamily.FourFunctions

Goal state before:
pp: case ha
α : Type u_1
β : Type u_2
inst✝⁴ : DecidableEq α
inst✝³ : CommSemiring β
inst✝² : LinearOrder β
inst✝¹ : IsStrictOrderedRing β
a : α
f₁ f₂ f₃ f₄ : Finset α → β
u : Finset α
inst✝ : ExistsAddOfLE β
hu : a ∉ u
h₁ : 0 ≤ f₁
h₂ : 0 ≤ f₂
h₃ : 0 ≤ f₃
h₄ : 0 ≤ f₄
h : ∀ ⦃s : Finset α⦄, s ⊆ insert a u → ∀ ⦃t : Finset α⦄, t ⊆ insert a u → f₁ s * f₂ t ≤ f₃ (s ∩ t) * f₄ (s ∪ t)
𝒜 ℬ : Finset (Finset α)
s : Finset α
hsu : s ⊆ u
t : Finset α
htu : t ⊆ u
this✝⁴ : s ⊆ insert a u
this✝³ : t ⊆ insert a u
this✝² : insert a s ⊆ insert a u
this✝¹ : insert a t ⊆ insert a u
has : a ∉ s
hat : a ∉ t
this✝ : a ∉ s ∩ t
this : a ∉ s ∪ t
h✝³ : s ∈ 𝒜
h✝² : insert a s ∉ 𝒜
h✝¹ : t ∈ ℬ
h✝ : insert a t ∈ ℬ
⊢ 0 ≤ f₄ (s ∪ t) + f₄ (s ∪ insert a t)

Tactic:
exact add_nonneg (h₄ _) (h₄ _)

Goal state after:
Module: Mathlib.Combinatorics.SimpleGraph.Connectivity.Connected

Goal state before:
pp: V : Type u
u v : V
⊢ (completeGraph V).Reachable u v

Tactic:
obtain rfl | huv := eq_or_ne u v

Goal state after:
case inl
V : Type u
u : V
⊢ (completeGraph V).Reachable u u

case inr
V : Type u
u v : V
huv : u ≠ v
⊢ (completeGraph V).Reachable u v
Module: Mathlib.Combinatorics.SimpleGraph.Connectivity.Connected

Goal state before:
pp: V : Type u
G : SimpleGraph V
v : V
h : G.IsUniversal v
u w : V
⊢ G.Reachable u w

Tactic:
exact (Reachable.of_isUniversal u h).symm.trans (Reachable.of_isUniversal w h)

Goal state after:
Module: Mathlib.Combinatorics.SetFamily.FourFunctions

Goal state before:
pp: case pos
α : Type u_1
β : Type u_2
inst✝⁴ : DecidableEq α
inst✝³ : CommSemiring β
inst✝² : LinearOrder β
inst✝¹ : IsStrictOrderedRing β
a : α
f₁ f₂ f₃ f₄ : Finset α → β
u : Finset α
inst✝ : ExistsAddOfLE β
hu : a ∉ u
h₁ : 0 ≤ f₁
h₂ : 0 ≤ f₂
h₃ : 0 ≤ f₃
h₄ : 0 ≤ f₄
h : ∀ ⦃s : Finset α⦄, s ⊆ insert a u → ∀ ⦃t : Finset α⦄, t ⊆ insert a u → f₁ s * f₂ t ≤ f₃ (s ∩ t) * f₄ (s ∪ t)
𝒜 ℬ : Finset (Finset α)
s : Finset α
hsu : s ⊆ u
t : Finset α
htu : t ⊆ u
this✝⁴ : s ⊆ insert a u
this✝³ : t ⊆ insert a u
this✝² : insert a s ⊆ insert a u
this✝¹ : insert a t ⊆ insert a u
has : a ∉ s
hat : a ∉ t
this✝ : a ∉ s ∩ t
this : a ∉ s ∪ t
h✝¹ : s ∉ 𝒜
h✝ : insert a s ∈ 𝒜
⊢ f₁ (insert a s) * collapse ℬ a f₂ t ≤ collapse (𝒜 ⊼ ℬ) a f₃ (s ∩ t) * collapse (𝒜 ⊻ ℬ) a f₄ (s ∪ t)

Tactic:
collapse_eq hat,

Goal state after:
case pos
α : Type u_1
β : Type u_2
inst✝⁴ : DecidableEq α
inst✝³ : CommSemiring β
inst✝² : LinearOrder β
inst✝¹ : IsStrictOrderedRing β
a : α
f₁ f₂ f₃ f₄ : Finset α → β
u : Finset α
inst✝ : ExistsAddOfLE β
hu : a ∉ u
h₁ : 0 ≤ f₁
h₂ : 0 ≤ f₂
h₃ : 0 ≤ f₃
h₄ : 0 ≤ f₄
h : ∀ ⦃s : Finset α⦄, s ⊆ insert a u → ∀ ⦃t : Finset α⦄, t ⊆ insert a u → f₁ s * f₂ t ≤ f₃ (s ∩ t) * f₄ (s ∪ t)
𝒜 ℬ : Finset (Finset α)
s : Finset α
hsu : s ⊆ u
t : Finset α
htu : t ⊆ u
this✝⁴ : s ⊆ insert a u
this✝³ : t ⊆ insert a u
this✝² : insert a s ⊆ insert a u
this✝¹ : insert a t ⊆ insert a u
has : a ∉ s
hat : a ∉ t
this✝ : a ∉ s ∩ t
this : a ∉ s ∪ t
h✝¹ : s ∉ 𝒜
h✝ : insert a s ∈ 𝒜
⊢ f₁ (insert a s) * ((if t ∈ ℬ then f₂ t else 0) + if insert a t ∈ ℬ then f₂ (insert a t) else 0) ≤
    collapse (𝒜 ⊼ ℬ) a f₃ (s ∩ t) * collapse (𝒜 ⊻ ℬ) a f₄ (s ∪ t)
Module: Mathlib.Combinatorics.SetFamily.KruskalKatona

Goal state before:
pp: n r k i : ℕ
𝒜 : Finset (Finset (Fin n))
hir : i ≤ r
hrk : r ≤ k
hkn : k ≤ n
h₁ : Set.Sized r ↑𝒜
h₂ : k.choose r ≤ #𝒜
range'k : Finset (Fin n) := (range k).attachFin ⋯
𝒞 : Finset (Finset (Fin n)) := powersetCard r range'k
this : Set.Sized r ↑𝒞
⊢ k.choose (r - i) ≤ #(∂^[i] 𝒜)

Tactic:
calc
    k.choose (r - i)
    _ = #(powersetCard (r - i) range'k) := by rw [card_powersetCard, card_attachFin, card_range]
    _ = #(∂^[i] 𝒞) := by
      congr!
      ext B
      rw [mem_powersetCard, mem_shadow_iterate_iff_exists_sdiff]
      constructor
      · rintro ⟨hBk, hB⟩
        have := exists_subsuperset_card_eq hBk (Nat.le_add_left _ i) <| by
          rwa [hB, card_attachFin, card_range, ← Nat.add_sub_assoc hir, Nat.add_sub_cancel_left]
        obtain ⟨C, BsubC, hCrange, hcard⟩ := this
        rw [hB, ← Nat.add_sub_assoc hir, Nat.add_sub_cancel_left] at hcard
        refine ⟨C, mem_powersetCard.2 ⟨hCrange, hcard⟩, BsubC, ?_⟩
        rw [card_sdiff_of_subset BsubC, hcard, hB, Nat.sub_sub_self hir]
      · rintro ⟨A, Ah, hBA, card_sdiff_i⟩
        rw [mem_powersetCard] at Ah
        refine ⟨hBA.trans Ah.1, eq_tsub_of_add_eq ?_⟩
        rw [← Ah.2, ← card_sdiff_i, add_comm, card_sdiff_add_card_eq_card hBA]
    _ ≤ #(∂^[i] 𝒜) := by
      refine iterated_kk h₁ ?_ ⟨‹_›, ?_⟩
      · rwa [card_powersetCard, card_attachFin, card_range]
      simp_rw [𝒞, mem_powersetCard]
      rintro A B hA ⟨HB₁, HB₂⟩
      refine ⟨fun t ht ↦ ?_, ‹_›⟩
      rw [mem_attachFin, mem_range]
      have : toColex (image Fin.val B) < toColex (image Fin.val A) := by
        rwa [toColex_image_lt_toColex_image Fin.val_strictMono]
      apply Colex.forall_lt_mono this.le _ t (mem_image.2 ⟨t, ht, rfl⟩)
      simp_rw [mem_image]
      rintro _ ⟨a, ha, hab⟩
      simpa [range'k, hab] using hA.1 ha

Goal state after:
Module: Mathlib.Combinatorics.SimpleGraph.Coloring.Vertex

Goal state before:
pp: case mpr.refine_2
V : Type u
G : SimpleGraph V
n : ℕ
C : G.Coloring ℕ
Cf : ∀ (v : V), C v < n
v w : V
hvw : G.Adj v w
⊢ ¬C v = C w

Tactic:
exact C.valid hvw

Goal state after:
Module: Mathlib.Combinatorics.SimpleGraph.Coloring.Vertex

Goal state before:
pp: V : Type u
G : SimpleGraph V
inst✝ : Subsingleton V
⊢ ∀ {v w : V}, G.Adj v w → 0 ≠ 0

Tactic:
intro v w

Goal state after:
V : Type u
G : SimpleGraph V
inst✝ : Subsingleton V
v w : V
⊢ G.Adj v w → 0 ≠ 0
Module: Mathlib.Combinatorics.SimpleGraph.Coloring.Vertex

Goal state before:
pp: V✝ : Type u
G : SimpleGraph V✝
n : ℕ
ι : Type u_1
α : Type u_2
β : Type u_3
C : G.Coloring α
V : Type u_4
W : Type u_5
⊢ ∀ {v w : V ⊕ W}, (completeBipartiteGraph V W).Adj v w → v.isRight ≠ w.isRight

Tactic:
intro v w

Goal state after:
V✝ : Type u
G : SimpleGraph V✝
n : ℕ
ι : Type u_1
α : Type u_2
β : Type u_3
C : G.Coloring α
V : Type u_4
W : Type u_5
v w : V ⊕ W
⊢ (completeBipartiteGraph V W).Adj v w → v.isRight ≠ w.isRight
Module: Mathlib.Combinatorics.SimpleGraph.Bipartite

Goal state before:
pp: V : Type u_1
G : SimpleGraph V
s t : Finset V
inst✝ : G.LocallyFinite
h : G.IsBipartiteWith ↑s ↑t
⊢ ∑ v ∈ s, G.degree v = ∑ w ∈ t, G.degree w

Tactic:
← sum_attach t,

Goal state after:
V : Type u_1
G : SimpleGraph V
s t : Finset V
inst✝ : G.LocallyFinite
h : G.IsBipartiteWith ↑s ↑t
⊢ ∑ v ∈ s, G.degree v = ∑ x ∈ t.attach, G.degree ↑x
Module: Mathlib.Combinatorics.SimpleGraph.Connectivity.EdgeConnectivity

Goal state before:
pp: case refine_1
V : Type u_1
G : SimpleGraph V
k : ℕ
u v : V
hk✝ : k ≠ 0
h : G.IsEdgeReachable (k + 1) u v
e : Sym2 V
s : Set (Sym2 V)
hk : s.encard < ↑k
⊢ ((G.deleteEdges {e}).deleteEdges s).Reachable u v

Tactic:
rw [deleteEdges_deleteEdges, Set.union_comm]

Goal state after:
case refine_1
V : Type u_1
G : SimpleGraph V
k : ℕ
u v : V
hk✝ : k ≠ 0
h : G.IsEdgeReachable (k + 1) u v
e : Sym2 V
s : Set (Sym2 V)
hk : s.encard < ↑k
⊢ (G.deleteEdges (s ∪ {e})).Reachable u v
Module: Mathlib.Combinatorics.SimpleGraph.Bipartite

Goal state before:
pp: V : Type u_1
G : SimpleGraph V
s t : Finset V
inst✝² : Fintype V
inst✝¹ : DecidableRel G.Adj
inst✝ : DecidableEq V
h : G.IsBipartiteWith ↑s ↑t
hsub : G.support.toFinset ⊆ s ∪ t
⊢ ∑ x ∈ G.support.toFinset, G.degree x = 2 * #G.edgeFinset

pp: V : Type u_1
G : SimpleGraph V
s t : Finset V
inst✝² : Fintype V
inst✝¹ : DecidableRel G.Adj
inst✝ : DecidableEq V
h : G.IsBipartiteWith ↑s ↑t
hsub : G.support.toFinset ⊆ s ∪ t
⊢ ∀ x ∈ s ∪ t, x ∉ G.support.toFinset → G.degree x = 0

Tactic:
← sum_degrees_support_eq_twice_card_edges

Goal state after:
V : Type u_1
G : SimpleGraph V
s t : Finset V
inst✝² : Fintype V
inst✝¹ : DecidableRel G.Adj
inst✝ : DecidableEq V
h : G.IsBipartiteWith ↑s ↑t
hsub : G.support.toFinset ⊆ s ∪ t
⊢ ∑ x ∈ G.support.toFinset, G.degree x = ∑ v ∈ G.support.toFinset, G.degree v

V : Type u_1
G : SimpleGraph V
s t : Finset V
inst✝² : Fintype V
inst✝¹ : DecidableRel G.Adj
inst✝ : DecidableEq V
h : G.IsBipartiteWith ↑s ↑t
hsub : G.support.toFinset ⊆ s ∪ t
⊢ ∀ x ∈ s ∪ t, x ∉ G.support.toFinset → G.degree x = 0
Module: Mathlib.Combinatorics.SimpleGraph.Bipartite

Goal state before:
pp: V : Type u_1
G : SimpleGraph V
c : V → Fin 2
hc : ∀ {a b : V}, G.Adj a b → (completeGraph (Fin 2)).Adj (c a) (c b)
⊢ Disjoint {v | c v = 0} {v | c v = 1}

Tactic:
aesop (add simp [Set.disjoint_left])

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

Goal state before:
pp: case cons.succ
V : Type u
G : SimpleGraph V
u v u✝ v✝ w✝ : V
hxy : G.Adj u✝ v✝
i' : G.Walk v✝ w✝
ih : ∀ {i : ℕ}, i < i'.length → i'.toSubgraph.Adj (i'.getVert i) (i'.getVert (i + 1))
n✝ : ℕ
hi : n✝ + 1 < (cons hxy i').length
⊢ (cons hxy i').toSubgraph.Adj ((cons hxy i').getVert (n✝ + 1)) ((cons hxy i').getVert (n✝ + 1 + 1))

Tactic:
simp only [Walk.toSubgraph, getVert_cons_succ, Subgraph.sup_adj, subgraphOfAdj_adj, Sym2.eq,
        Sym2.rel_iff', Prod.mk.injEq, Prod.swap_prod_mk]
      right
      exact ih (Nat.succ_lt_succ_iff.mp hi)

Goal state after:
Module: Mathlib.Combinatorics.SetFamily.FourFunctions

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝⁵ : DistribLattice α
inst✝⁴ : CommSemiring β
inst✝³ : LinearOrder β
inst✝² : IsStrictOrderedRing β
inst✝¹ : ExistsAddOfLE β
f₁ f₂ f₃ f₄ : α → β
inst✝ : DecidableEq α
h₁ : 0 ≤ f₁
h₂ : 0 ≤ f₂
h₃ : 0 ≤ f₃
h₄ : 0 ≤ f₄
h : ∀ (a b : α), f₁ a * f₂ b ≤ f₃ (a ⊓ b) * f₄ (a ⊔ b)
s t : Finset α
⊢ (∑ a ∈ s, f₁ a) * ∑ a ∈ t, f₂ a ≤ (∑ a ∈ s ⊼ t, f₃ a) * ∑ a ∈ s ⊻ t, f₄ a

Tactic:
by
  classical
  set L : Sublattice α := ⟨latticeClosure (s ∪ t), isSublattice_latticeClosure.1,
    isSublattice_latticeClosure.2⟩
  have : Finite L := (s.finite_toSet.union t.finite_toSet).latticeClosure.to_subtype
  set s' : Finset L := s.preimage (↑) Subtype.coe_injective.injOn
  set t' : Finset L := t.preimage (↑) Subtype.coe_injective.injOn
  have hs' : s'.map ⟨L.subtype, Subtype.coe_injective⟩ = s := by
    simpa [s', map_eq_image, image_preimage, filter_eq_self] using!
      fun a ha ↦ subset_latticeClosure <| Set.subset_union_left ha
  have ht' : t'.map ⟨L.subtype, Subtype.coe_injective⟩ = t := by
    simpa [t', map_eq_image, image_preimage, filter_eq_self] using!
      fun a ha ↦ subset_latticeClosure <| Set.subset_union_right ha
  clear_value s' t'
  obtain ⟨β, _, _, g, hg⟩ := exists_birkhoff_representation L
  have := four_functions_theorem_aux (extend g (f₁ ∘ (↑)) 0) (extend g (f₂ ∘ (↑)) 0)
    (extend g (f₃ ∘ (↑)) 0) (extend g (f₄ ∘ (↑)) 0) (extend_nonneg (fun _ ↦ h₁ _) le_rfl)
    (extend_nonneg (fun _ ↦ h₂ _) le_rfl) (extend_nonneg (fun _ ↦ h₃ _) le_rfl)
    (extend_nonneg (fun _ ↦ h₄ _) le_rfl) ?_ (s'.map ⟨g, hg⟩) (t'.map ⟨g, hg⟩)
  · simpa only [← hs', ← ht', ← map_sups, ← map_infs, sum_map, Embedding.coeFn_mk, hg.extend_apply]
      using! this
  rintro s t
  obtain ⟨a, rfl⟩ | hs := em (∃ a, g a = s)
  · obtain ⟨b, rfl⟩ | ht := em (∃ b, g b = t)
    · simp_rw [← sup_eq_union, ← inf_eq_inter, ← map_sup, ← map_inf, hg.extend_apply]
      exact h _ _
    · simpa [extend_apply' _ _ _ ht] using! mul_nonneg
        (extend_nonneg (fun a : L ↦ h₃ a) le_rfl _) (extend_nonneg (fun a : L ↦ h₄ a) le_rfl _)
  · simpa [extend_apply' _ _ _ hs] using! mul_nonneg
      (extend_nonneg (fun a : L ↦ h₃ a) le_rfl _) (extend_nonneg (fun a : L ↦ h₄ a) le_rfl _)

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

Goal state before:
pp: V : Type u_1
G : SimpleGraph V
α : Type u_2
β : Type u_3
inst✝³ : Finite α
inst✝² : Finite β
inst✝¹ : Nonempty α
inst✝ : Nonempty β
this✝ : Fintype α
this : Fintype β
x✝ :
  ∃ left right, #left = Fintype.card α ∧ #right = Fintype.card β ∧ G.bipartiteDoubleCover.IsCompleteBetween ↑left ↑right
left right : Finset (V ⊕ V)
card_left : #left = Fintype.card α
card_right : #right = Fintype.card β
h : G.bipartiteDoubleCover.IsCompleteBetween ↑left ↑right
l : V
hl : Sum.inl l ∈ left
hmem_left :
  ∀ {l' : V ⊕ V},
    l' ∈ left → ((Sum.inl l).isLeft = true → l'.isLeft = true) ∧ ((Sum.inl l).isRight = true → l'.isRight = true)
r : V
hr : Sum.inr r ∈ right
hmem_right :
  ∀ {r' : V ⊕ V},
    r' ∈ right → ((Sum.inr r).isLeft = true → r'.isLeft = true) ∧ ((Sum.inr r).isRight = true → r'.isRight = true)
j : V
hj : j ∈ right.toRight
⊢ Sum.inr j ∈ right

Tactic:
by simpa using hj

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

Goal state before:
pp: V : Type u_1
G : SimpleGraph V
α : Type u_2
β : Type u_3
inst✝³ : Finite α
inst✝² : Finite β
inst✝¹ : Nonempty α
inst✝ : Nonempty β
this✝ : Fintype α
this : Fintype β
x✝ :
  ∃ left right, #left = Fintype.card α ∧ #right = Fintype.card β ∧ G.bipartiteDoubleCover.IsCompleteBetween ↑left ↑right
left right : Finset (V ⊕ V)
card_left : #left = Fintype.card α
card_right : #right = Fintype.card β
h : G.bipartiteDoubleCover.IsCompleteBetween ↑left ↑right
l : V
hl : Sum.inr l ∈ left
hmem_left :
  ∀ {l' : V ⊕ V},
    l' ∈ left → ((Sum.inr l).isLeft = true → l'.isLeft = true) ∧ ((Sum.inr l).isRight = true → l'.isRight = true)
r : V
hr : Sum.inl r ∈ right
hmem_right :
  ∀ {r' : V ⊕ V},
    r' ∈ right → ((Sum.inl r).isLeft = true → r'.isLeft = true) ∧ ((Sum.inl r).isRight = true → r'.isRight = true)
j : V
hj : j ∈ right.toLeft
⊢ Sum.inl j ∈ right

Tactic:
by simpa using hj

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

Goal state before:
pp: case mp
V : Type u_1
G : SimpleGraph V
hc : G.Connected
hu : ∀ (u v : V) (x y : G.Path u v), x = y
⊢ ∀ (v w : V), ∃! p, p.IsPath

Tactic:
intro v w

Goal state after:
case mp
V : Type u_1
G : SimpleGraph V
hc : G.Connected
hu : ∀ (u v : V) (x y : G.Path u v), x = y
v w : V
⊢ ∃! p, p.IsPath
Module: Mathlib.Combinatorics.SimpleGraph.Acyclic

Goal state before:
pp: case mpr.refine_1
V : Type u_1
G : SimpleGraph V
hV : Nonempty V
h : ∀ (v w : V), ∃! p, p.IsPath
⊢ G.Preconnected

Tactic:
intro v w

Goal state after:
case mpr.refine_1
V : Type u_1
G : SimpleGraph V
hV : Nonempty V
h : ∀ (v w : V), ∃! p, p.IsPath
v w : V
⊢ G.Reachable v w
Module: Mathlib.Combinatorics.SimpleGraph.Coloring.Constructions

Goal state before:
pp: case a
n : ℕ
h : 2 ≤ n
hc : (pathGraph n).Colorable (Fintype.card Bool)
⊢ 2 ≤ (pathGraph n).chromaticNumber

Tactic:
· have hadj : (pathGraph n).Adj ⟨0, Nat.zero_lt_of_lt h⟩ ⟨1, h⟩ := by simp [pathGraph_adj]
    exact two_le_chromaticNumber_of_adj hadj

Goal state after:
Module: Mathlib.Combinatorics.SimpleGraph.Coloring.Constructions

Goal state before:
pp: n : ℕ
h : 2 ≤ n
hOdd : Odd n
hc : (cycleGraph n).Colorable (Fintype.card (Fin 3))
⊢ ¬2 = n

Tactic:
intro h2

Goal state after:
n : ℕ
h : 2 ≤ n
hOdd : Odd n
hc : (cycleGraph n).Colorable (Fintype.card (Fin 3))
h2 : 2 = n
⊢ False
Module: Mathlib.Combinatorics.SimpleGraph.CompleteMultipartite

Goal state before:
pp: α : Type u
G : SimpleGraph α
s : Set α
v w₁ w₂ : α
h : G.IsPathGraph3Compl v w₁ w₂
a✝ b✝ : Fin 3
this✝ : G.Adj w₁ w₂
this : G.Adj w₂ w₁
h1 : ¬G.Adj w₁ v
h2 : ¬G.Adj w₂ v
⊢ ¬G.Adj w₁ v ∧ ¬G.Adj w₂ v

Tactic:
exact ⟨h1, h2⟩

Goal state after:
Module: Mathlib.Combinatorics.SimpleGraph.Extremal.Turan

Goal state before:
pp: n r : ℕ
| r * (r - 1)

Tactic:
enter [1]

Goal state after:
n r : ℕ
| r
Module: Mathlib.Combinatorics.SimpleGraph.Diam

Goal state before:
pp: α : Type u_1
G : SimpleGraph α
inst✝ : Nonempty α
⊢ G.center = Set.univ ↔ ∃ e, ∀ (u : α), G.eccent u = e

Tactic:
← Set.univ_subset_iff

Goal state after:
α : Type u_1
G : SimpleGraph α
inst✝ : Nonempty α
⊢ Set.univ ⊆ G.center ↔ ∃ e, ∀ (u : α), G.eccent u = e
Module: Mathlib.Combinatorics.SimpleGraph.Extremal.Turan

Goal state before:
pp: n✝ r : ℕ
hr : r > 0
n : ℕ
⊢ (n ^ 2 - (n % r) ^ 2) * (r - 1) / (2 * r) = n % r * (n / r) * (r - 1) + r * (r - 1) * (n / r) ^ 2 / 2

Tactic:
← Nat.mod_add_div n r,

Goal state after:
n✝ r : ℕ
hr : r > 0
n : ℕ
⊢ ((n % r + r * (n / r)) ^ 2 - (n % r) ^ 2) * (r - 1) / (2 * r) =
    n % r * (n / r) * (r - 1) + r * (r - 1) * (n / r) ^ 2 / 2
Module: Mathlib.Combinatorics.SimpleGraph.CompleteMultipartite

Goal state before:
pp: case neg.refine_5
α : Type u
G✝ : SimpleGraph α
s : Set α
V : Type u_1
G : SimpleGraph V
r t : ℕ
K : G.CompleteEquipartiteSubgraph r t
f : (completeEquipartiteGraph r t).Copy G
ht : ¬t = 0
x✝³ x✝² : Finset V
hne : x✝³ ≠ x✝²
x✝¹ : V
h₁' : x✝¹ ∈ ↑x✝³
x✝ : V
h₂' : x✝ ∈ ↑x✝²
h₁ : x✝³ ∈ (fun i ↦ map { toFun := fun j ↦ f (i, j), inj' := ⋯ } univ) '' ↑univ
h₂ : x✝² ∈ (fun i ↦ map { toFun := fun j ↦ f (i, j), inj' := ⋯ } univ) '' ↑univ
⊢ G.Adj x✝¹ x✝

Tactic:
coe_univ,

Goal state after:
case neg.refine_5
α : Type u
G✝ : SimpleGraph α
s : Set α
V : Type u_1
G : SimpleGraph V
r t : ℕ
K : G.CompleteEquipartiteSubgraph r t
f : (completeEquipartiteGraph r t).Copy G
ht : ¬t = 0
x✝³ x✝² : Finset V
hne : x✝³ ≠ x✝²
x✝¹ : V
h₁' : x✝¹ ∈ ↑x✝³
x✝ : V
h₂' : x✝ ∈ ↑x✝²
h₁ : x✝³ ∈ (fun i ↦ map { toFun := fun j ↦ f (i, j), inj' := ⋯ } univ) '' Set.univ
h₂ : x✝² ∈ (fun i ↦ map { toFun := fun j ↦ f (i, j), inj' := ⋯ } univ) '' Set.univ
⊢ G.Adj x✝¹ x✝