Metamath Proof Explorer


Theorem uspgrunop

Description: The union of two simple pseudographs (with the same vertex set): If <. V , E >. and <. V , F >. are simple pseudographs, then <. V , E u. F >. is a pseudograph (the vertex set stays the same, but the edges from both graphs are kept, maybe resulting incident two edges between two vertices). (Contributed by Alexander van der Vekens, 10-Aug-2017) (Revised by AV, 16-Oct-2020) (Revised by AV, 24-Oct-2021)

Ref Expression
Hypotheses uspgrun.g φ G USHGraph
uspgrun.h φ H USHGraph
uspgrun.e E = iEdg G
uspgrun.f F = iEdg H
uspgrun.vg V = Vtx G
uspgrun.vh φ Vtx H = V
uspgrun.i φ dom E dom F =
Assertion uspgrunop φ V E F UPGraph

Proof

Step Hyp Ref Expression
1 uspgrun.g φ G USHGraph
2 uspgrun.h φ H USHGraph
3 uspgrun.e E = iEdg G
4 uspgrun.f F = iEdg H
5 uspgrun.vg V = Vtx G
6 uspgrun.vh φ Vtx H = V
7 uspgrun.i φ dom E dom F =
8 uspgrupgr G USHGraph G UPGraph
9 1 8 syl φ G UPGraph
10 uspgrupgr H USHGraph H UPGraph
11 2 10 syl φ H UPGraph
12 9 11 3 4 5 6 7 upgrunop φ V E F UPGraph