Metamath Proof Explorer


Theorem struct2grvtx

Description: The set of vertices of a graph represented as an extensible structure with vertices as base set and indexed edges. (Contributed by AV, 23-Sep-2020)

Ref Expression
Hypothesis struct2grvtx.g G = Base ndx V ef ndx E
Assertion struct2grvtx V X E Y Vtx G = V

Proof

Step Hyp Ref Expression
1 struct2grvtx.g G = Base ndx V ef ndx E
2 edgfndxnn ef ndx
3 baseltedgf Base ndx < ef ndx
4 2 3 1 structvtxval V X E Y Vtx G = V