Metamath Proof Explorer


Theorem clnbgrn0

Description: The closed neighborhood of a vertex is never empty. (Contributed by AV, 16-May-2025)

Ref Expression
Hypothesis clnbgrn0.v V = Vtx G
Assertion clnbgrn0 Could not format assertion : No typesetting found for |- ( N e. V -> ( G ClNeighbVtx N ) =/= (/) ) with typecode |-

Proof

Step Hyp Ref Expression
1 clnbgrn0.v V = Vtx G
2 1 clnbgrvtxel Could not format ( N e. V -> N e. ( G ClNeighbVtx N ) ) : No typesetting found for |- ( N e. V -> N e. ( G ClNeighbVtx N ) ) with typecode |-
3 ne0i Could not format ( N e. ( G ClNeighbVtx N ) -> ( G ClNeighbVtx N ) =/= (/) ) : No typesetting found for |- ( N e. ( G ClNeighbVtx N ) -> ( G ClNeighbVtx N ) =/= (/) ) with typecode |-
4 2 3 syl Could not format ( N e. V -> ( G ClNeighbVtx N ) =/= (/) ) : No typesetting found for |- ( N e. V -> ( G ClNeighbVtx N ) =/= (/) ) with typecode |-