let G3 be _Graph; for v1, e being object
for v2 being Vertex of G3
for G2 being addVertex of G3,v1
for G1 being addEdge of G2,v1,e,v2 st not e in the_Edges_of G3 & not v1 in the_Vertices_of G3 holds
G1 is addAdjVertex of G3,v1,e,v2
let v1, e be object ; for v2 being Vertex of G3
for G2 being addVertex of G3,v1
for G1 being addEdge of G2,v1,e,v2 st not e in the_Edges_of G3 & not v1 in the_Vertices_of G3 holds
G1 is addAdjVertex of G3,v1,e,v2
let v2 be Vertex of G3; for G2 being addVertex of G3,v1
for G1 being addEdge of G2,v1,e,v2 st not e in the_Edges_of G3 & not v1 in the_Vertices_of G3 holds
G1 is addAdjVertex of G3,v1,e,v2
let G2 be addVertex of G3,v1; for G1 being addEdge of G2,v1,e,v2 st not e in the_Edges_of G3 & not v1 in the_Vertices_of G3 holds
G1 is addAdjVertex of G3,v1,e,v2
let G1 be addEdge of G2,v1,e,v2; ( not e in the_Edges_of G3 & not v1 in the_Vertices_of G3 implies G1 is addAdjVertex of G3,v1,e,v2 )
assume A1:
( not e in the_Edges_of G3 & not v1 in the_Vertices_of G3 )
; G1 is addAdjVertex of G3,v1,e,v2
A2:
G1 is Supergraph of G3
by Th66;
A3:
( the_Vertices_of G2 = (the_Vertices_of G3) \/ {v1} & the_Edges_of G2 = the_Edges_of G3 & the_Source_of G2 = the_Source_of G3 & the_Target_of G2 = the_Target_of G3 )
by Def10;
A5:
v2 is Vertex of G2
by Th72;
v1 is Vertex of G2
by Th98;
then
( the_Vertices_of G1 = the_Vertices_of G2 & the_Edges_of G1 = (the_Edges_of G2) \/ {e} & the_Source_of G1 = (the_Source_of G2) +* (e .--> v1) & the_Target_of G1 = (the_Target_of G2) +* (e .--> v2) )
by A1, A3, A5, Def11;
hence
G1 is addAdjVertex of G3,v1,e,v2
by A1, A2, A3, Def14; verum