Metamath Proof Explorer


Theorem usgrexmpl1

Description: G is a simple graph of six vertices 0 , 1 , 2 , 3 , 4 , 5 , with edges { 0 , 1 } , { 1 , 2 } , { 0 , 2 } , { 0 , 3 } , { 3 , 4 } , { 3 , 5 } , { 4 , 5 } . (Contributed by AV, 3-Aug-2025)

Ref Expression
Hypotheses usgrexmpl1.v ⊢ V = 0 … 5
usgrexmpl1.e ⊢ E = ⟨“ 0 1 0 2 1 2 0 3 3 4 3 5 4 5 ”⟩
usgrexmpl1.g ⊢ G = V E
Assertion usgrexmpl1 ⊢ G ∈ USGraph

Proof

Step Hyp Ref Expression
1 usgrexmpl1.v ⊢ V = 0 … 5
2 usgrexmpl1.e ⊢ E = ⟨“ 0 1 0 2 1 2 0 3 3 4 3 5 4 5 ”⟩
3 usgrexmpl1.g ⊢ G = V E
4 1 2 usgrexmpl1lem ⊢ E : dom ⁡ E ⟶ 1-1 e ∈ 𝒫 V | e = 2
5 3 eleq1i ⊢ G ∈ USGraph ↔ V E ∈ USGraph
6 1 ovexi ⊢ V ∈ V
7 s7cli ⊢ ⟨“ 0 1 0 2 1 2 0 3 3 4 3 5 4 5 ”⟩ ∈ Word V
8 2 7 eqeltri ⊢ E ∈ Word V
9 isusgrop ⊢ V ∈ V ∧ E ∈ Word V → V E ∈ USGraph ↔ E : dom ⁡ E ⟶ 1-1 e ∈ 𝒫 V | e = 2
10 6 8 9 mp2an ⊢ V E ∈ USGraph ↔ E : dom ⁡ E ⟶ 1-1 e ∈ 𝒫 V | e = 2
11 5 10 bitri ⊢ G ∈ USGraph ↔ E : dom ⁡ E ⟶ 1-1 e ∈ 𝒫 V | e = 2
12 4 11 mpbir ⊢ G ∈ USGraph