set V = {1,2};
set E = {} ;
reconsider S = {} as Function of {} ,{1,2} by RELSET_1:25;
set G = createGraph {1,2},{} ,S,S;
take
createGraph {1,2},{} ,S,S
; ( createGraph {1,2},{} ,S,S is finite & not createGraph {1,2},{} ,S,S is trivial & createGraph {1,2},{} ,S,S is simple )
A2:
the_Edges_of (createGraph {1,2},{} ,S,S) = {}
by FINSEQ_4:91;
A3:
the_Vertices_of (createGraph {1,2},{} ,S,S) = {1,2}
by FINSEQ_4:91;
hence
createGraph {1,2},{} ,S,S is finite
by A2, Def19; ( not createGraph {1,2},{} ,S,S is trivial & createGraph {1,2},{} ,S,S is simple )
card (the_Vertices_of (createGraph {1,2},{} ,S,S)) <> 1
by A3, CARD_2:76;
hence
not createGraph {1,2},{} ,S,S is trivial
by Def21; createGraph {1,2},{} ,S,S is simple
for e being set holds
( not e in the_Edges_of (createGraph {1,2},{} ,S,S) or not (the_Source_of (createGraph {1,2},{} ,S,S)) . e = (the_Target_of (createGraph {1,2},{} ,S,S)) . e )
by FINSEQ_4:91;
then A4:
createGraph {1,2},{} ,S,S is loopless
by Def20;
for e1, e2, v1, v2 being set st e1 Joins v1,v2, createGraph {1,2},{} ,S,S & e2 Joins v1,v2, createGraph {1,2},{} ,S,S holds
e1 = e2
by A2, Def15;
then
createGraph {1,2},{} ,S,S is non-multi
by Def22;
hence
createGraph {1,2},{} ,S,S is simple
by A4; verum