Module: Mathlib.Combinatorics.SimpleGraph.CompleteMultipartite

Goal state before:
pp: case neg.refine_1
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
i : Fin r
x✝¹ x✝ : Fin t
h : (fun j ↦ f (i, j)) x✝¹ = (fun j ↦ f (i, j)) x✝
⊢ x✝¹ = x✝

pp: case neg.refine_2
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
i₁ i₂ : Fin r
h :
  (fun i ↦ map { toFun := fun j ↦ f (i, j), inj' := ⋯ } univ) i₁ =
    (fun i ↦ map { toFun := fun j ↦ f (i, j), inj' := ⋯ } univ) i₂
⊢ i₁ = i₂

pp: case neg.refine_3
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
⊢ #(map { toFun := fun i ↦ map { toFun := fun j ↦ f (i, j), inj' := ⋯ } univ, inj' := ⋯ } univ) = r ∨ t = 0

pp: case neg.refine_4
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
p✝ : Finset V
h : p✝ ∈ map { toFun := fun i ↦ map { toFun := fun j ↦ f (i, j), inj' := ⋯ } univ, inj' := ⋯ } univ
⊢ #p✝ = t

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 : Finset V
h₁ : x✝³ ∈ ↑(map { toFun := fun i ↦ map { toFun := fun j ↦ f (i, j), inj' := ⋯ } univ, inj' := ⋯ } univ)
x✝² : Finset V
h₂ : x✝² ∈ ↑(map { toFun := fun i ↦ map { toFun := fun j ↦ f (i, j), inj' := ⋯ } univ, inj' := ⋯ } univ)
hne : x✝³ ≠ x✝²
x✝¹ : V
h₁' : x✝¹ ∈ ↑x✝³
x✝ : V
h₂' : x✝ ∈ ↑x✝²
⊢ G.Adj x✝¹ x✝

Tactic:
· simpa using f.injective h

Goal state after:
case neg.refine_2
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
i₁ i₂ : Fin r
h :
  (fun i ↦ map { toFun := fun j ↦ f (i, j), inj' := ⋯ } univ) i₁ =
    (fun i ↦ map { toFun := fun j ↦ f (i, j), inj' := ⋯ } univ) i₂
⊢ i₁ = i₂

case neg.refine_3
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
⊢ #(map { toFun := fun i ↦ map { toFun := fun j ↦ f (i, j), inj' := ⋯ } univ, inj' := ⋯ } univ) = r ∨ t = 0

case neg.refine_4
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
p✝ : Finset V
h : p✝ ∈ map { toFun := fun i ↦ map { toFun := fun j ↦ f (i, j), inj' := ⋯ } univ, inj' := ⋯ } univ
⊢ #p✝ = t

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 : Finset V
h₁ : x✝³ ∈ ↑(map { toFun := fun i ↦ map { toFun := fun j ↦ f (i, j), inj' := ⋯ } univ, inj' := ⋯ } univ)
x✝² : Finset V
h₂ : x✝² ∈ ↑(map { toFun := fun i ↦ map { toFun := fun j ↦ f (i, j), inj' := ⋯ } univ, inj' := ⋯ } univ)
hne : x✝³ ≠ x✝²
x✝¹ : V
h₁' : x✝¹ ∈ ↑x✝³
x✝ : V
h₂' : x✝ ∈ ↑x✝²
⊢ G.Adj x✝¹ x✝