Metamath Proof Explorer


Theorem usgrexmpl2

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

Ref Expression
Hypotheses usgrexmpl2.v V = 0 5
usgrexmpl2.e E = ⟨“ 0 1 1 2 2 3 3 4 4 5 0 3 0 5 ”⟩
usgrexmpl2.g G = V E
Assertion usgrexmpl2 G USGraph

Proof

Step Hyp Ref Expression
1 usgrexmpl2.v V = 0 5
2 usgrexmpl2.e E = ⟨“ 0 1 1 2 2 3 3 4 4 5 0 3 0 5 ”⟩
3 usgrexmpl2.g G = V E
4 1 2 usgrexmpl2lem 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 1 2 2 3 3 4 4 5 0 3 0 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