Metamath Proof Explorer


Theorem clnbgrvtxedg

Description: An edge E containing a vertex A is an edge in the closed neighborhood of this vertex A . (Contributed by AV, 25-Dec-2025)

Ref Expression
Hypotheses clnbgrvtxedg.n
|- N = ( G ClNeighbVtx A )
clnbgrvtxedg.i
|- I = ( Edg ` G )
clnbgrvtxedg.k
|- K = { x e. I | x C_ N }
Assertion clnbgrvtxedg
|- ( ( G e. UHGraph /\ E e. I /\ A e. E ) -> E e. K )

Proof

Step Hyp Ref Expression
1 clnbgrvtxedg.n
 |-  N = ( G ClNeighbVtx A )
2 clnbgrvtxedg.i
 |-  I = ( Edg ` G )
3 clnbgrvtxedg.k
 |-  K = { x e. I | x C_ N }
4 simp2
 |-  ( ( G e. UHGraph /\ E e. I /\ A e. E ) -> E e. I )
5 2 1 clnbgrssedg
 |-  ( ( G e. UHGraph /\ E e. I /\ A e. E ) -> E C_ N )
6 sseq1
 |-  ( x = E -> ( x C_ N <-> E C_ N ) )
7 6 3 elrab2
 |-  ( E e. K <-> ( E e. I /\ E C_ N ) )
8 4 5 7 sylanbrc
 |-  ( ( G e. UHGraph /\ E e. I /\ A e. E ) -> E e. K )