let G, G2 be _Graph; for V being set
for G1 being addVertices of G,V st G1 == G2 holds
G2 is addVertices of G,V
let V be set ; for G1 being addVertices of G,V st G1 == G2 holds
G2 is addVertices of G,V
let G1 be addVertices of G,V; ( G1 == G2 implies G2 is addVertices of G,V )
assume A1:
G1 == G2
; G2 is addVertices of G,V
then
( the_Vertices_of G1 = the_Vertices_of G2 & the_Edges_of G1 = the_Edges_of G2 & the_Target_of G1 = the_Target_of G2 & the_Source_of G1 = the_Source_of G2 )
by GLIB_000:def 34;
then A2:
( the_Vertices_of G2 = (the_Vertices_of G) \/ V & the_Edges_of G2 = the_Edges_of G & the_Source_of G2 = the_Source_of G & the_Target_of G2 = the_Target_of G )
by Def10;
G2 is Supergraph of G1
by A1, Th62;
then
G2 is Supergraph of G
by Th66;
hence
G2 is addVertices of G,V
by A2, Def10; verum