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

Goal state before:
pp: n : ℕ
G : SimpleGraph (Fin n)
inst✝ : DecidableRel G.Adj
r t t' : ℕ
K : G.CompleteEquipartiteSubgraph r t'
v : Fin n
ht'_pos : 0 < t'
hv : v ∈ K.vertsᶜ
p : Finset (Fin n)
hp : p ∈ K.parts
hs : ∀ (x : Finset (Fin n)), x ∉ powersetCard t p ∨ ∃ x_1 ∈ x, ¬G.Adj v x_1
⊢ #({v_1 ∈ K.verts | (between (↑K.verts) (↑K.verts)ᶜ G).Adj v_1 v}) < #K.verts - t' + t

Tactic:
conv =>
    enter [1, 1, 2]
    unfold CompleteEquipartiteSubgraph.verts

Goal state after:
n : ℕ
G : SimpleGraph (Fin n)
inst✝ : DecidableRel G.Adj
r t t' : ℕ
K : G.CompleteEquipartiteSubgraph r t'
v : Fin n
ht'_pos : 0 < t'
hv : v ∈ K.vertsᶜ
p : Finset (Fin n)
hp : p ∈ K.parts
hs : ∀ (x : Finset (Fin n)), x ∉ powersetCard t p ∨ ∃ x_1 ∈ x, ¬G.Adj v x_1
⊢ #({v_1 ∈ K.parts.disjiUnion id ⋯ | (between (↑K.verts) (↑K.verts)ᶜ G).Adj v_1 v}) < #K.verts - t' + t
Module: Mathlib.Combinatorics.SimpleGraph.Extremal.ErdosStoneSimonovits

Goal state before:
pp: case h₁
n : ℕ
G : SimpleGraph (Fin n)
inst✝ : DecidableRel G.Adj
r t t' : ℕ
K : G.CompleteEquipartiteSubgraph r t'
v : Fin n
ht'_pos : 0 < t'
hv : v ∈ K.vertsᶜ
p : Finset (Fin n)
hp : p ∈ K.parts
hs : ∀ (x : Finset (Fin n)), x ∉ powersetCard t p ∨ ∃ x_1 ∈ x, ¬G.Adj v x_1
⊢ ∑ x ∈ K.parts \ {p}, #({v_1 ∈ id x | (between (↑K.verts) (↑K.verts)ᶜ G).Adj v_1 v}) ≤ #K.verts - t'

Tactic:
conv_rhs =>
      rw [K.card_verts, ← Nat.sub_one_mul, ← K.card_parts.resolve_right ht'_pos.ne',
        ← card_singleton p, ← Finset.card_sdiff_of_subset (singleton_subset_iff.mpr hp),
        ← smul_eq_mul, ← sum_const,
        ← Finset.sum_congr rfl fun _ h ↦ K.card_mem_parts (mem_sdiff.mp h).1]
    exact sum_le_sum (fun _ _ ↦ card_filter_le _ _)

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

Goal state before:
pp: case h₁
n : ℕ
G : SimpleGraph (Fin n)
inst✝ : DecidableRel G.Adj
r t t' : ℕ
K : G.CompleteEquipartiteSubgraph r t'
hr_pos : 0 < r
ht'_pos : 0 < t'
v : Fin n
hv : v ∈ K.vertsᶜ \ filter K t
⊢ ↑((between (↑K.verts) (↑K.verts)ᶜ G).degree v) ≤ ↑(#K.verts) - ↑t' + ↑t

pp: case h₂
n : ℕ
G : SimpleGraph (Fin n)
inst✝ : DecidableRel G.Adj
r t t' : ℕ
K : G.CompleteEquipartiteSubgraph r t'
hr_pos : 0 < r
ht'_pos : 0 < t'
v : Fin n
hv : v ∈ filter K t
⊢ ↑((between (↑K.verts) (↑K.verts)ᶜ G).degree v) ≤ ↑(#K.verts)

Tactic:
· rw [← Nat.cast_sub ((Nat.le_mul_of_pos_left t' hr_pos).trans_eq K.card_verts.symm)]
          exact_mod_cast (degree_between_verts_lt_of_mem_sdiff K hv ht'_pos).le

Goal state after:
case h₂
n : ℕ
G : SimpleGraph (Fin n)
inst✝ : DecidableRel G.Adj
r t t' : ℕ
K : G.CompleteEquipartiteSubgraph r t'
hr_pos : 0 < r
ht'_pos : 0 < t'
v : Fin n
hv : v ∈ filter K t
⊢ ↑((between (↑K.verts) (↑K.verts)ᶜ G).degree v) ≤ ↑(#K.verts)
Module: Mathlib.Combinatorics.SimpleGraph.Matching

Goal state before:
pp: case h
V : Type u_1
G : SimpleGraph V
s t : Set V
h : Disjoint s t
f : ↑s ≃ ↑t
hadj : ∀ (v : ↑s), G.Adj ↑v ↑(f v)
v : V
hr : v ∈ t
⊢ (fun w ↦ (∃ (h : v ∈ s), ↑(f ⟨v, h⟩) = w) ∨ ∃ (h : w ∈ s), ↑(f ⟨w, h⟩) = v) ↑(f.symm ⟨v, hr⟩) ∧
    ∀ (y : V), (fun w ↦ (∃ (h : v ∈ s), ↑(f ⟨v, h⟩) = w) ∨ ∃ (h : w ∈ s), ↑(f ⟨w, h⟩) = v) y → y = ↑(f.symm ⟨v, hr⟩)

Tactic:
simp only [Subtype.coe_eta, Equiv.apply_symm_apply, Subtype.coe_prop, exists_const, or_true,
      true_and]

Goal state after:
case h
V : Type u_1
G : SimpleGraph V
s t : Set V
h : Disjoint s t
f : ↑s ≃ ↑t
hadj : ∀ (v : ↑s), G.Adj ↑v ↑(f v)
v : V
hr : v ∈ t
⊢ ∀ (y : V), ((∃ (h : v ∈ s), ↑(f ⟨v, h⟩) = y) ∨ ∃ (h : y ∈ s), ↑(f ⟨y, h⟩) = v) → y = ↑(f.symm ⟨v, hr⟩)
Module: Mathlib.Combinatorics.SimpleGraph.IncMatrix

Goal state before:
pp: R : Type u_1
α : Type u_2
G : SimpleGraph α
inst✝³ : Fintype (Sym2 α)
inst✝² : DecidableEq α
inst✝¹ : DecidableRel G.Adj
inst✝ : Semiring R
a b : α
h : G.Adj a b
⊢ {x | x ∈ G.incidenceSet a ∩ G.incidenceSet b} = {s(a, b)}

Tactic:
rw [← coe_eq_singleton, coe_filter_univ]

Goal state after:
R : Type u_1
α : Type u_2
G : SimpleGraph α
inst✝³ : Fintype (Sym2 α)
inst✝² : DecidableEq α
inst✝¹ : DecidableRel G.Adj
inst✝ : Semiring R
a b : α
h : G.Adj a b
⊢ {x | x ∈ G.incidenceSet a ∩ G.incidenceSet b} = {s(a, b)}
Module: Mathlib.Combinatorics.SimpleGraph.Matching

Goal state before:
pp: case h
V : Type u_1
G : SimpleGraph V
M : G.Subgraph
inst✝ : Finite V
u : Set V
hM : M.IsPerfectMatching
c : ↑(⊤.deleteVerts u).coe.oddComponents
h : ∀ w ∈ u, ∀ (v : ↑(⊤.deleteVerts u).verts), M.Adj (↑v) w → v ∉ (↑c).supp
w v' : V
hv' : v' ∈ (⊤.deleteVerts u).verts
hv : ⟨v', hv'⟩ ∈ (↑c).supp
hw : (fun w ↦ M.Adj (↑⟨v', hv'⟩) w) w ∧ ∀ (y : V), (fun w ↦ M.Adj (↑⟨v', hv'⟩) w) y → y = w
⊢ (fun w ↦ (M.induce (Subtype.val '' (↑c).supp)).Adj (↑⟨v', hv'⟩) w) w ∧
    ∀ (y : V), (fun w ↦ (M.induce (Subtype.val '' (↑c).supp)).Adj (↑⟨v', hv'⟩) w) y → y = w

Tactic:
have hwnu : w ∉ u := fun hw' ↦ h w hw' ⟨v', hv'⟩ (hw.1) hv

Goal state after:
case h
V : Type u_1
G : SimpleGraph V
M : G.Subgraph
inst✝ : Finite V
u : Set V
hM : M.IsPerfectMatching
c : ↑(⊤.deleteVerts u).coe.oddComponents
h : ∀ w ∈ u, ∀ (v : ↑(⊤.deleteVerts u).verts), M.Adj (↑v) w → v ∉ (↑c).supp
w v' : V
hv' : v' ∈ (⊤.deleteVerts u).verts
hv : ⟨v', hv'⟩ ∈ (↑c).supp
hw : (fun w ↦ M.Adj (↑⟨v', hv'⟩) w) w ∧ ∀ (y : V), (fun w ↦ M.Adj (↑⟨v', hv'⟩) w) y → y = w
hwnu : w ∉ u
⊢ (fun w ↦ (M.induce (Subtype.val '' (↑c).supp)).Adj (↑⟨v', hv'⟩) w) w ∧
    ∀ (y : V), (fun w ↦ (M.induce (Subtype.val '' (↑c).supp)).Adj (↑⟨v', hv'⟩) w) y → y = w
Module: Mathlib.Combinatorics.SimpleGraph.FiveWheelLike

Goal state before:
pp: case refine_2
α : Type u_1
G : SimpleGraph α
r k : ℕ
x v w₁ w₂ : α
s t : Finset α
inst✝¹ : DecidableEq α
hw : G.IsFiveWheelLike r k v w₁ w₂ s t
hcf : G.CliqueFree (r + 2)
inst✝ : DecidableRel G.Adj
hW : ∀ ⦃y : α⦄, y ∈ s ∩ t → G.Adj x y
h2 : #({z ∈ {v} ∪ ({w₁} ∪ ({w₂} ∪ (s ∪ t))) | ¬G.Adj x z}) ≤ 2
a b c d : α
haj : ¬G.Adj x a
hbj : ¬G.Adj x b
hab : a ≠ b
hat : a ∉ t
hbs : b ∉ s
W : Finset α := {v} ∪ ({w₁} ∪ ({w₂} ∪ (s ∪ t)))
hcj : ¬G.Adj x a
hbc : b ≠ a
hca : True
hdj : ¬G.Adj x b
had : a ≠ b
hdb : True
ha : a = w₁ ∨ a ∈ s
hb : b = w₂ ∨ b ∈ t
hc : a = v ∨ a ∈ s
hd : b = v ∨ b ∈ t
has : a ∈ s
hbt : b ∈ t
hav : a ≠ v
hbv : b ≠ v
haw : a ≠ w₂
hbw : b ≠ w₁
⊢ w₁ ≠ x

Tactic:
by_cases hax : x = a <;> rintro rfl
      · grind
      · exact haj <| hw.isNClique_fst_left.1 (mem_insert_self ..) (mem_insert_of_mem has) hax

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

Goal state before:
pp: α : Type u_1
G : SimpleGraph α
r k : ℕ
v w₁ w₂ : α
s t : Finset α
inst✝² : DecidableEq α
hw : G.IsFiveWheelLike r k v w₁ w₂ s t
hcf : G.CliqueFree (r + 2)
inst✝¹ : DecidableRel G.Adj
inst✝ : Fintype α
hm : G.FiveWheelLikeFree r (k + 1)
X : Finset α := {x | ∀ ⦃y : α⦄, y ∈ s ∩ t → G.Adj x y}
W : Finset α := {v} ∪ ({w₁} ∪ ({w₂} ∪ (s ∪ t)))
x✝ : α
⊢ x✝ ∈ X → 3 ≤ #({z ∈ W | ¬G.Adj x✝ z})

Tactic:
hx

Goal state after:
α : Type u_1
G : SimpleGraph α
r k : ℕ
v w₁ w₂ : α
s t : Finset α
inst✝² : DecidableEq α
hw : G.IsFiveWheelLike r k v w₁ w₂ s t
hcf : G.CliqueFree (r + 2)
inst✝¹ : DecidableRel G.Adj
inst✝ : Fintype α
hm : G.FiveWheelLikeFree r (k + 1)
X : Finset α := {x | ∀ ⦃y : α⦄, y ∈ s ∩ t → G.Adj x y}
W : Finset α := {v} ∪ ({w₁} ∪ ({w₂} ∪ (s ∪ t)))
x✝ : α
hx : x✝ ∈ X
⊢ 3 ≤ #({z ∈ W | ¬G.Adj x✝ z})
Module: Mathlib.Combinatorics.SimpleGraph.FiveWheelLike

Goal state before:
pp: α : Type u_1
G : SimpleGraph α
r k : ℕ
v w₁ w₂ : α
s t : Finset α
inst✝² : DecidableEq α
hw : G.IsFiveWheelLike r k v w₁ w₂ s t
hcf : G.CliqueFree (r + 2)
inst✝¹ : DecidableRel G.Adj
inst✝ : Fintype α
hm : G.FiveWheelLikeFree r (k + 1)
X : Finset α := {x | ∀ ⦃y : α⦄, y ∈ s ∩ t → G.Adj x y}
W : Finset α := {v} ∪ ({w₁} ∪ ({w₂} ∪ (s ∪ t)))
dXle : ∀ x ∈ X, 3 ≤ #({z ∈ W | ¬G.Adj x z})
one_le : ∀ (x : α), 1 ≤ #({z ∈ {v} ∪ ({w₁} ∪ ({w₂} ∪ (s ∪ t))) | ¬G.Adj x z})
bdW : ∑ w ∈ W, G.degree w ≤ #X * (#W - 3) + #Xᶜ * (#W - 1)
x : α
⊢ x ∈ Xᶜ → 1 ≤ #({z ∈ s ∩ t | ¬G.Adj x z})

Tactic:
hx

Goal state after:
α : Type u_1
G : SimpleGraph α
r k : ℕ
v w₁ w₂ : α
s t : Finset α
inst✝² : DecidableEq α
hw : G.IsFiveWheelLike r k v w₁ w₂ s t
hcf : G.CliqueFree (r + 2)
inst✝¹ : DecidableRel G.Adj
inst✝ : Fintype α
hm : G.FiveWheelLikeFree r (k + 1)
X : Finset α := {x | ∀ ⦃y : α⦄, y ∈ s ∩ t → G.Adj x y}
W : Finset α := {v} ∪ ({w₁} ∪ ({w₂} ∪ (s ∪ t)))
dXle : ∀ x ∈ X, 3 ≤ #({z ∈ W | ¬G.Adj x z})
one_le : ∀ (x : α), 1 ≤ #({z ∈ {v} ∪ ({w₁} ∪ ({w₂} ∪ (s ∪ t))) | ¬G.Adj x z})
bdW : ∑ w ∈ W, G.degree w ≤ #X * (#W - 3) + #Xᶜ * (#W - 1)
x : α
hx : x ∈ Xᶜ
⊢ 1 ≤ #({z ∈ s ∩ t | ¬G.Adj x z})
Module: Mathlib.Combinatorics.SimpleGraph.StronglyRegular

Goal state before:
pp: case e'_3.e'_5
n k ℓ μ : ℕ
V : Type u
inst✝¹ : Fintype V
G : SimpleGraph V
inst✝ : DecidableRel G.Adj
h : G.IsSRGWith n k ℓ μ
this : DecidableEq V := Classical.decEq V
v : V
⊢ n - k - 1 = #(Gᶜ.neighborFinset v)

pp: case convert_3
n k ℓ μ : ℕ
V : Type u
inst✝¹ : Fintype V
G : SimpleGraph V
inst✝ : DecidableRel G.Adj
h : G.IsSRGWith n k ℓ μ
this : DecidableEq V := Classical.decEq V
v : V
⊢ ∀ a ∈ G.neighborFinset v, #(bipartiteAbove G.Adj (Gᶜ.neighborFinset v) a) = k - ℓ - 1

pp: case convert_4
n k ℓ μ : ℕ
V : Type u
inst✝¹ : Fintype V
G : SimpleGraph V
inst✝ : DecidableRel G.Adj
h : G.IsSRGWith n k ℓ μ
this : DecidableEq V := Classical.decEq V
v : V
⊢ ∀ b ∈ Gᶜ.neighborFinset v, #(bipartiteBelow G.Adj (G.neighborFinset v) b) = μ

Tactic:
· simp [h.compl.regular v]

Goal state after:
case convert_3
n k ℓ μ : ℕ
V : Type u
inst✝¹ : Fintype V
G : SimpleGraph V
inst✝ : DecidableRel G.Adj
h : G.IsSRGWith n k ℓ μ
this : DecidableEq V := Classical.decEq V
v : V
⊢ ∀ a ∈ G.neighborFinset v, #(bipartiteAbove G.Adj (Gᶜ.neighborFinset v) a) = k - ℓ - 1

case convert_4
n k ℓ μ : ℕ
V : Type u
inst✝¹ : Fintype V
G : SimpleGraph V
inst✝ : DecidableRel G.Adj
h : G.IsSRGWith n k ℓ μ
this : DecidableEq V := Classical.decEq V
v : V
⊢ ∀ b ∈ Gᶜ.neighborFinset v, #(bipartiteBelow G.Adj (G.neighborFinset v) b) = μ
Module: Mathlib.Combinatorics.SimpleGraph.StronglyRegular

Goal state before:
pp: case convert_4
n k ℓ μ : ℕ
V : Type u
inst✝¹ : Fintype V
G : SimpleGraph V
inst✝ : DecidableRel G.Adj
h : G.IsSRGWith n k ℓ μ
this : DecidableEq V := Classical.decEq V
v w : V
hw : ¬G.Adj v w ∧ w ≠ v
⊢ #(bipartiteBelow G.Adj (G.neighborFinset v) w) = μ

Tactic:
bipartiteBelow,

Goal state after:
case convert_4
n k ℓ μ : ℕ
V : Type u
inst✝¹ : Fintype V
G : SimpleGraph V
inst✝ : DecidableRel G.Adj
h : G.IsSRGWith n k ℓ μ
this : DecidableEq V := Classical.decEq V
v w : V
hw : ¬G.Adj v w ∧ w ≠ v
⊢ #({a ∈ G.neighborFinset v | G.Adj a w}) = μ
Module: Mathlib.Combinatorics.SimpleGraph.StronglyRegular

Goal state before:
pp: case neg
V : Type u
inst✝³ : Fintype V
G : SimpleGraph V
inst✝² : DecidableRel G.Adj
n k ℓ μ : ℕ
inst✝¹ : DecidableEq V
α : Type u_1
inst✝ : Semiring α
h : G.IsSRGWith n k ℓ μ
v w : V
hn : v ≠ w
ha : ¬G.Adj v w
⊢ ↑(Fintype.card ↑(G.commonNeighbors v w)) = ↑μ

Tactic:
· rw [h.of_not_adj hn ha]

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

Goal state before:
pp: V : Type u_1
G : SimpleGraph V
inst✝¹ : Nonempty V
inst✝ : Finite V
⊢ G.vertexCoverNum < ENat.card V

Tactic:
by
  refine (ENat.add_one_le_iff vertexCoverNum_ne_top_of_finite).mp ?_
  grw [vertexCoverNum_le_card_sub_one, ENat.card_eq_coe_natCard]
  enat_to_nat
  exact Nat.add_le_of_le_sub (Order.one_le_iff_pos.mpr Nat.card_pos) (le_refl _)

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

Goal state before:
pp: case refine_2
V : Type u_1
a✝ : Nontrivial V
n : ℕ
hn : ↑n ≤ ENat.card V - 1
hh : (completeGraph V).vertexCoverNum < ↑n
⊢ False

Tactic:
have : n - 1 ≤ ENat.card V := by
    grw [tsub_le_iff_right, hn]
    simp [add_assoc, one_add_one_eq_two]

Goal state after:
case refine_2
V : Type u_1
a✝ : Nontrivial V
n : ℕ
hn : ↑n ≤ ENat.card V - 1
hh : (completeGraph V).vertexCoverNum < ↑n
this : ↑n - 1 ≤ ENat.card V
⊢ False
Module: Mathlib.Combinatorics.SimpleGraph.Tutte

Goal state before:
pp: case refine_2
V : Type u_1
G G' : SimpleGraph V
x b a c : V
M : (G ⊔ edge a c).Subgraph
p : G'.Walk a x
hp : p.IsPath
hcalt : G'.IsAlternating M.spanningCoe
hM2nadj : ¬M.Adj x a
hpac : p.toSubgraph.Adj a c
hnpxb : ¬p.toSubgraph.Adj x b
hM2ac : M.Adj a c
hgadj : G.Adj x a
hnxc : x ≠ c
hnab : a ≠ b
hle : p.toSubgraph.spanningCoe ≤ G ⊔ edge a c
aux : ∀ (c' : V), c' ≠ a → p.toSubgraph.Adj c' x → M.Adj c' x
⊢ (p.toSubgraph.spanningCoe ⊔ edge x a).IsCycles

Tactic:
refine hp.isCycles_spanningCoe_toSubgraph_sup_edge hgadj.ne.symm fun hadj ↦ ?_

Goal state after:
case refine_2
V : Type u_1
G G' : SimpleGraph V
x b a c : V
M : (G ⊔ edge a c).Subgraph
p : G'.Walk a x
hp : p.IsPath
hcalt : G'.IsAlternating M.spanningCoe
hM2nadj : ¬M.Adj x a
hpac : p.toSubgraph.Adj a c
hnpxb : ¬p.toSubgraph.Adj x b
hM2ac : M.Adj a c
hgadj : G.Adj x a
hnxc : x ≠ c
hnab : a ≠ b
hle : p.toSubgraph.spanningCoe ≤ G ⊔ edge a c
aux : ∀ (c' : V), c' ≠ a → p.toSubgraph.Adj c' x → M.Adj c' x
hadj : s(x, a) ∈ p.edges
⊢ False
Module: Mathlib.Combinatorics.SimpleGraph.Tutte

Goal state before:
pp: case intro
V : Type u_1
G : SimpleGraph V
inst✝ : Finite V
hveven : Even (Nat.card V)
h : ¬G.IsTutteViolator G.universalVerts
h' : ∀ (K : G.deleteUniversalVerts.coe.ConnectedComponent), G.deleteUniversalVerts.coe.IsClique K.supp
val✝ : Fintype V
M : G.Subgraph
hM : M.IsMatching
hsub : M.vertsᶜ ⊆ G.universalVerts
⊢ ∃ M, M.IsPerfectMatching

Tactic:
obtain ⟨M', hM'⟩ := ((G.isClique_universalVerts.subset hsub).even_iff_exists_isMatching
    (Set.toFinite _)).mp (by simpa [Set.even_ncard_compl_iff hveven, -Set.toFinset_card,
      ← Set.ncard_eq_toFinset_card'] using hM.even_card)

Goal state after:
case intro
V : Type u_1
G : SimpleGraph V
inst✝ : Finite V
hveven : Even (Nat.card V)
h : ¬G.IsTutteViolator G.universalVerts
h' : ∀ (K : G.deleteUniversalVerts.coe.ConnectedComponent), G.deleteUniversalVerts.coe.IsClique K.supp
val✝ : Fintype V
M : G.Subgraph
hM : M.IsMatching
hsub : M.vertsᶜ ⊆ G.universalVerts
M' : G.Subgraph
hM' : M'.verts = M.vertsᶜ ∧ M'.IsMatching
⊢ ∃ M, M.IsPerfectMatching
Module: Mathlib.Combinatorics.SimpleGraph.Tutte

Goal state before:
pp: case neg
V : Type u_1
G : SimpleGraph V
inst✝ : Finite V
x a b c : V
M1 : (G ⊔ edge x b).Subgraph
M2 : (G ⊔ edge a c).Subgraph
hxa : G.Adj x a
hab : G.Adj a b
hnGxb : ¬G.Adj x b
hnGac : ¬G.Adj a c
hnxb : x ≠ b
hnxc : x ≠ c
hnac : a ≠ c
hnbc : b ≠ c
hM1 : M1.IsPerfectMatching
hM2 : M2.IsPerfectMatching
hM1xb : M1.Adj x b
hM2ac : M2.Adj a c
hM1nac : ¬M1.Adj a c
hsupG : G ⊔ edge x b ⊔ (G ⊔ edge a c) = G ⊔ edge a c ⊔ edge x b
cycles : SimpleGraph V := M1.spanningCoe ∆ M2.spanningCoe
hcalt : cycles.IsAlternating M2.spanningCoe
hcycles : (M1.spanningCoe ∆ M2.spanningCoe).IsCycles
hcac : cycles.Adj a c
hM1sub : M1.spanningCoe ≤ G ⊔ edge x b
hM2sub : M2.spanningCoe ≤ G ⊔ edge a c
induce_le : (cycles.connectedComponentMk c).toSimpleGraph.spanningCoe ≤ G ⊔ edge a c ⊔ edge x b
⊢ ∃ G', G'.IsAlternating M2.spanningCoe ∧ G'.IsCycles ∧ ¬G'.Adj x b ∧ G'.Adj a c ∧ G' ≤ G ⊔ edge a c

Tactic:
by_cases! hxc : x ∉ (cycles.connectedComponentMk c).supp

Goal state after:
case pos
V : Type u_1
G : SimpleGraph V
inst✝ : Finite V
x a b c : V
M1 : (G ⊔ edge x b).Subgraph
M2 : (G ⊔ edge a c).Subgraph
hxa : G.Adj x a
hab : G.Adj a b
hnGxb : ¬G.Adj x b
hnGac : ¬G.Adj a c
hnxb : x ≠ b
hnxc : x ≠ c
hnac : a ≠ c
hnbc : b ≠ c
hM1 : M1.IsPerfectMatching
hM2 : M2.IsPerfectMatching
hM1xb : M1.Adj x b
hM2ac : M2.Adj a c
hM1nac : ¬M1.Adj a c
hsupG : G ⊔ edge x b ⊔ (G ⊔ edge a c) = G ⊔ edge a c ⊔ edge x b
cycles : SimpleGraph V := M1.spanningCoe ∆ M2.spanningCoe
hcalt : cycles.IsAlternating M2.spanningCoe
hcycles : (M1.spanningCoe ∆ M2.spanningCoe).IsCycles
hcac : cycles.Adj a c
hM1sub : M1.spanningCoe ≤ G ⊔ edge x b
hM2sub : M2.spanningCoe ≤ G ⊔ edge a c
induce_le : (cycles.connectedComponentMk c).toSimpleGraph.spanningCoe ≤ G ⊔ edge a c ⊔ edge x b
hxc : x ∉ (cycles.connectedComponentMk c).supp
⊢ ∃ G', G'.IsAlternating M2.spanningCoe ∧ G'.IsCycles ∧ ¬G'.Adj x b ∧ G'.Adj a c ∧ G' ≤ G ⊔ edge a c

case neg
V : Type u_1
G : SimpleGraph V
inst✝ : Finite V
x a b c : V
M1 : (G ⊔ edge x b).Subgraph
M2 : (G ⊔ edge a c).Subgraph
hxa : G.Adj x a
hab : G.Adj a b
hnGxb : ¬G.Adj x b
hnGac : ¬G.Adj a c
hnxb : x ≠ b
hnxc : x ≠ c
hnac : a ≠ c
hnbc : b ≠ c
hM1 : M1.IsPerfectMatching
hM2 : M2.IsPerfectMatching
hM1xb : M1.Adj x b
hM2ac : M2.Adj a c
hM1nac : ¬M1.Adj a c
hsupG : G ⊔ edge x b ⊔ (G ⊔ edge a c) = G ⊔ edge a c ⊔ edge x b
cycles : SimpleGraph V := M1.spanningCoe ∆ M2.spanningCoe
hcalt : cycles.IsAlternating M2.spanningCoe
hcycles : (M1.spanningCoe ∆ M2.spanningCoe).IsCycles
hcac : cycles.Adj a c
hM1sub : M1.spanningCoe ≤ G ⊔ edge x b
hM2sub : M2.spanningCoe ≤ G ⊔ edge a c
induce_le : (cycles.connectedComponentMk c).toSimpleGraph.spanningCoe ≤ G ⊔ edge a c ⊔ edge x b
hxc : x ∈ (cycles.connectedComponentMk c).supp
⊢ ∃ G', G'.IsAlternating M2.spanningCoe ∧ G'.IsCycles ∧ ¬G'.Adj x b ∧ G'.Adj a c ∧ G' ≤ G ⊔ edge a c
Module: Mathlib.Data.Nat.PSub

Goal state before:
pp: m n : ℕ
⊢ (m - n).ppred.getD 0 = (m.psub (n + 1)).getD 0

Tactic:
rw [sub_eq_psub m n, psub]; cases psub m n <;> rfl

Goal state after:
Module: Mathlib.Computability.Primrec.Basic

Goal state before:
pp: α : Type u_1
β : Type u_2
σ : Type u_3
inst✝² : Primcodable α
inst✝¹ : Primcodable β
inst✝ : Primcodable σ
o : α → Option β
f : α → σ
g : α → β → σ
ho : Primrec o
hf : Primrec f
hg : Primrec₂ g
a : α
⊢ (Nat.casesOn (encode (o a)) (encode (f a)) fun b ↦
      (encode ((decode (encode (a, b).1)).bind fun a ↦ Option.map (g a) (decode b))).pred) =
    encode (Option.casesOn (o a) (f a) (g a))

Tactic:
rcases o a with - | b

Goal state after:
case none
α : Type u_1
β : Type u_2
σ : Type u_3
inst✝² : Primcodable α
inst✝¹ : Primcodable β
inst✝ : Primcodable σ
o : α → Option β
f : α → σ
g : α → β → σ
ho : Primrec o
hf : Primrec f
hg : Primrec₂ g
a : α
⊢ (Nat.casesOn (encode none) (encode (f a)) fun b ↦
      (encode ((decode (encode (a, b).1)).bind fun a ↦ Option.map (g a) (decode b))).pred) =
    encode (Option.casesOn none (f a) (g a))

case some
α : Type u_1
β : Type u_2
σ : Type u_3
inst✝² : Primcodable α
inst✝¹ : Primcodable β
inst✝ : Primcodable σ
o : α → Option β
f : α → σ
g : α → β → σ
ho : Primrec o
hf : Primrec f
hg : Primrec₂ g
a : α
b : β
⊢ (Nat.casesOn (encode (some b)) (encode (f a)) fun b ↦
      (encode ((decode (encode (a, b).1)).bind fun a ↦ Option.map (g a) (decode b))).pred) =
    encode (Option.casesOn (some b) (f a) (g a))
Module: Mathlib.Computability.Partrec

Goal state before:
pp: α : Type u_1
f : ℕ → Option α
H : ∀ {a : α} {m n : ℕ}, m ≤ n → a ∈ f m → a ∈ f n
a : α
x✝ : ∃ n, a ∈ f n
n : ℕ
h : a ∈ f n
⊢ a ∈ rfindOpt f

Tactic:
have h' := rfindOpt_dom.2 ⟨_, _, h⟩
    obtain ⟨k, hk⟩ := rfindOpt_spec ⟨h', rfl⟩
    have := (H (le_max_left _ _) h).symm.trans (H (le_max_right _ _) hk)
    simp at this; simp [this, get_mem]

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

Goal state before:
pp: case inl
V : Type u_1
G : SimpleGraph V
inst✝ : Finite V
a b c : V
M2 : (G ⊔ edge a c).Subgraph
hab : G.Adj a b
hnGac : ¬G.Adj a c
hnac : a ≠ c
hnbc : b ≠ c
hM2 : M2.IsPerfectMatching
hM2ac : M2.Adj a c
hM2sub : M2.spanningCoe ≤ G ⊔ edge a c
this : (G : SimpleGraph V) → G.LocallyFinite
hnM2 : ∀ (x' : V), x' ≠ c → ¬M2.Adj x' a
x'✝ x' c' : V
hc : c' ≠ a
w : V
M1 : (G ⊔ edge x' b).Subgraph
hxa : G.Adj x' a
hnGxb : ¬G.Adj x' b
hnxb : x' ≠ b
hnxc : x' ≠ c
hM1 : M1.IsPerfectMatching
hM1xb : M1.Adj x' b
hM1nac : ¬M1.Adj a c
hsupG : G ⊔ edge x' b ⊔ (G ⊔ edge a c) = G ⊔ edge a c ⊔ edge x' b
cycles : SimpleGraph V := M1.spanningCoe ∆ M2.spanningCoe
hcalt : cycles.IsAlternating M2.spanningCoe
hcycles : (M1.spanningCoe ∆ M2.spanningCoe).IsCycles
hcac : cycles.Adj a c
hM1sub : M1.spanningCoe ≤ G ⊔ edge x' b
induce_le : (cycles.connectedComponentMk c).toSimpleGraph.spanningCoe ≤ G ⊔ edge a c ⊔ edge x' b
hxc : x' ∈ (cycles.connectedComponentMk c).supp
hacc : a ∈ (cycles.connectedComponentMk c).supp
hx' : x'✝ ∈ {x', b}
p : cycles.Walk a x'✝
hp : p.IsPath
hpac : p.toSubgraph.Adj a c
hnpxb : ¬p.toSubgraph.Adj x' b
hle : p.toSubgraph.spanningCoe ≤ G ⊔ edge a c
hadj : p.toSubgraph.Adj c' x'
hl : (M1.spanningCoe \ M2.spanningCoe).Adj c' x'
hw : ∀ (y : V), (fun w ↦ M1.Adj x' w) y → y = w
⊢ p.toSubgraph.Adj x' w

Tactic:
← hw _ hl.1.symm

Goal state after:
case inl
V : Type u_1
G : SimpleGraph V
inst✝ : Finite V
a b c : V
M2 : (G ⊔ edge a c).Subgraph
hab : G.Adj a b
hnGac : ¬G.Adj a c
hnac : a ≠ c
hnbc : b ≠ c
hM2 : M2.IsPerfectMatching
hM2ac : M2.Adj a c
hM2sub : M2.spanningCoe ≤ G ⊔ edge a c
this : (G : SimpleGraph V) → G.LocallyFinite
hnM2 : ∀ (x' : V), x' ≠ c → ¬M2.Adj x' a
x'✝ x' c' : V
hc : c' ≠ a
w : V
M1 : (G ⊔ edge x' b).Subgraph
hxa : G.Adj x' a
hnGxb : ¬G.Adj x' b
hnxb : x' ≠ b
hnxc : x' ≠ c
hM1 : M1.IsPerfectMatching
hM1xb : M1.Adj x' b
hM1nac : ¬M1.Adj a c
hsupG : G ⊔ edge x' b ⊔ (G ⊔ edge a c) = G ⊔ edge a c ⊔ edge x' b
cycles : SimpleGraph V := M1.spanningCoe ∆ M2.spanningCoe
hcalt : cycles.IsAlternating M2.spanningCoe
hcycles : (M1.spanningCoe ∆ M2.spanningCoe).IsCycles
hcac : cycles.Adj a c
hM1sub : M1.spanningCoe ≤ G ⊔ edge x' b
induce_le : (cycles.connectedComponentMk c).toSimpleGraph.spanningCoe ≤ G ⊔ edge a c ⊔ edge x' b
hxc : x' ∈ (cycles.connectedComponentMk c).supp
hacc : a ∈ (cycles.connectedComponentMk c).supp
hx' : x'✝ ∈ {x', b}
p : cycles.Walk a x'✝
hp : p.IsPath
hpac : p.toSubgraph.Adj a c
hnpxb : ¬p.toSubgraph.Adj x' b
hle : p.toSubgraph.spanningCoe ≤ G ⊔ edge a c
hadj : p.toSubgraph.Adj c' x'
hl : (M1.spanningCoe \ M2.spanningCoe).Adj c' x'
hw : ∀ (y : V), (fun w ↦ M1.Adj x' w) y → y = w
⊢ p.toSubgraph.Adj x' c'
Module: Mathlib.Combinatorics.SimpleGraph.Tutte

Goal state before:
pp: case inr
V : Type u_1
G : SimpleGraph V
inst✝ : Finite V
x a c : V
M2 : (G ⊔ edge a c).Subgraph
hxa : G.Adj x a
hnGac : ¬G.Adj a c
hnxc : x ≠ c
hnac : a ≠ c
hM2 : M2.IsPerfectMatching
hM2ac : M2.Adj a c
hM2sub : M2.spanningCoe ≤ G ⊔ edge a c
this : (G : SimpleGraph V) → G.LocallyFinite
hnM2 : ∀ (x' : V), x' ≠ c → ¬M2.Adj x' a
x'✝ x' c' : V
hc : c' ≠ a
w : V
M1 : (G ⊔ edge x x').Subgraph
hab : G.Adj a x'
hnGxb : ¬G.Adj x x'
hnxb : x ≠ x'
hnbc : x' ≠ c
hM1 : M1.IsPerfectMatching
hM1xb : M1.Adj x x'
hM1nac : ¬M1.Adj a c
hsupG : G ⊔ edge x x' ⊔ (G ⊔ edge a c) = G ⊔ edge a c ⊔ edge x x'
cycles : SimpleGraph V := M1.spanningCoe ∆ M2.spanningCoe
hcalt : cycles.IsAlternating M2.spanningCoe
hcycles : (M1.spanningCoe ∆ M2.spanningCoe).IsCycles
hcac : cycles.Adj a c
hM1sub : M1.spanningCoe ≤ G ⊔ edge x x'
induce_le : (cycles.connectedComponentMk c).toSimpleGraph.spanningCoe ≤ G ⊔ edge a c ⊔ edge x x'
hxc : x ∈ (cycles.connectedComponentMk c).supp
hacc : a ∈ (cycles.connectedComponentMk c).supp
hx' : x'✝ ∈ {x, x'}
p : cycles.Walk a x'✝
hp : p.IsPath
hpac : p.toSubgraph.Adj a c
hnpxb : ¬p.toSubgraph.Adj x x'
hle : p.toSubgraph.spanningCoe ≤ G ⊔ edge a c
hadj : p.toSubgraph.Adj c' x'
hl : (M1.spanningCoe \ M2.spanningCoe).Adj c' x'
hw : ∀ (y : V), (fun w ↦ M1.Adj x' w) y → y = w
⊢ p.toSubgraph.Adj w x'

Tactic:
← hw _ hl.1.symm

Goal state after:
case inr
V : Type u_1
G : SimpleGraph V
inst✝ : Finite V
x a c : V
M2 : (G ⊔ edge a c).Subgraph
hxa : G.Adj x a
hnGac : ¬G.Adj a c
hnxc : x ≠ c
hnac : a ≠ c
hM2 : M2.IsPerfectMatching
hM2ac : M2.Adj a c
hM2sub : M2.spanningCoe ≤ G ⊔ edge a c
this : (G : SimpleGraph V) → G.LocallyFinite
hnM2 : ∀ (x' : V), x' ≠ c → ¬M2.Adj x' a
x'✝ x' c' : V
hc : c' ≠ a
w : V
M1 : (G ⊔ edge x x').Subgraph
hab : G.Adj a x'
hnGxb : ¬G.Adj x x'
hnxb : x ≠ x'
hnbc : x' ≠ c
hM1 : M1.IsPerfectMatching
hM1xb : M1.Adj x x'
hM1nac : ¬M1.Adj a c
hsupG : G ⊔ edge x x' ⊔ (G ⊔ edge a c) = G ⊔ edge a c ⊔ edge x x'
cycles : SimpleGraph V := M1.spanningCoe ∆ M2.spanningCoe
hcalt : cycles.IsAlternating M2.spanningCoe
hcycles : (M1.spanningCoe ∆ M2.spanningCoe).IsCycles
hcac : cycles.Adj a c
hM1sub : M1.spanningCoe ≤ G ⊔ edge x x'
induce_le : (cycles.connectedComponentMk c).toSimpleGraph.spanningCoe ≤ G ⊔ edge a c ⊔ edge x x'
hxc : x ∈ (cycles.connectedComponentMk c).supp
hacc : a ∈ (cycles.connectedComponentMk c).supp
hx' : x'✝ ∈ {x, x'}
p : cycles.Walk a x'✝
hp : p.IsPath
hpac : p.toSubgraph.Adj a c
hnpxb : ¬p.toSubgraph.Adj x x'
hle : p.toSubgraph.spanningCoe ≤ G ⊔ edge a c
hadj : p.toSubgraph.Adj c' x'
hl : (M1.spanningCoe \ M2.spanningCoe).Adj c' x'
hw : ∀ (y : V), (fun w ↦ M1.Adj x' w) y → y = w
⊢ p.toSubgraph.Adj c' x'