let G be _Graph; for V1, V2 being Subset of (the_Vertices_of G)
for G1 being addLoops of G,V1
for G2 being addLoops of G1,V2 st V1 misses V2 holds
G2 is addLoops of G,V1 \/ V2
let V1, V2 be Subset of (the_Vertices_of G); for G1 being addLoops of G,V1
for G2 being addLoops of G1,V2 st V1 misses V2 holds
G2 is addLoops of G,V1 \/ V2
let G1 be addLoops of G,V1; for G2 being addLoops of G1,V2 st V1 misses V2 holds
G2 is addLoops of G,V1 \/ V2
let G2 be addLoops of G1,V2; ( V1 misses V2 implies G2 is addLoops of G,V1 \/ V2 )
assume A1:
V1 misses V2
; G2 is addLoops of G,V1 \/ V2
consider E1 being set , f1 being one-to-one Function such that
A2:
( E1 misses the_Edges_of G & the_Edges_of G1 = (the_Edges_of G) \/ E1 & dom f1 = E1 & rng f1 = V1 & the_Source_of G1 = (the_Source_of G) +* f1 & the_Target_of G1 = (the_Target_of G) +* f1 )
by Def5;
V2 c= the_Vertices_of G
;
then
V2 c= the_Vertices_of G1
by Th15;
then consider E2 being set , f2 being one-to-one Function such that
A3:
( E2 misses the_Edges_of G1 & the_Edges_of G2 = (the_Edges_of G1) \/ E2 & dom f2 = E2 & rng f2 = V2 & the_Source_of G2 = (the_Source_of G1) +* f2 & the_Target_of G2 = (the_Target_of G1) +* f2 )
by Def5;
A4:
G2 is Supergraph of G
by GLIB_006:62;
A5: the_Vertices_of G2 =
the_Vertices_of G1
by Th15
.=
the_Vertices_of G
by Th15
;
now ex E being set ex f being one-to-one Function st
( E misses the_Edges_of G & the_Edges_of G2 = (the_Edges_of G) \/ E & dom f = E & rng f = V1 \/ V2 & the_Source_of G2 = (the_Source_of G) +* f & the_Target_of G2 = (the_Target_of G) +* f )reconsider E =
E1 \/ E2 as
set ;
reconsider f =
f1 +* f2 as
one-to-one Function by A1, A2, A3, FUNCT_4:92;
take E =
E;
ex f being one-to-one Function st
( E misses the_Edges_of G & the_Edges_of G2 = (the_Edges_of G) \/ E & dom f = E & rng f = V1 \/ V2 & the_Source_of G2 = (the_Source_of G) +* f & the_Target_of G2 = (the_Target_of G) +* f )take f =
f;
( E misses the_Edges_of G & the_Edges_of G2 = (the_Edges_of G) \/ E & dom f = E & rng f = V1 \/ V2 & the_Source_of G2 = (the_Source_of G) +* f & the_Target_of G2 = (the_Target_of G) +* f )A6:
(
E2 misses the_Edges_of G &
E2 misses E1 )
by A2, A3, XBOOLE_1:70;
hence
E misses the_Edges_of G
by A2, XBOOLE_1:70;
( the_Edges_of G2 = (the_Edges_of G) \/ E & dom f = E & rng f = V1 \/ V2 & the_Source_of G2 = (the_Source_of G) +* f & the_Target_of G2 = (the_Target_of G) +* f )thus
the_Edges_of G2 = (the_Edges_of G) \/ E
by A2, A3, XBOOLE_1:4;
( dom f = E & rng f = V1 \/ V2 & the_Source_of G2 = (the_Source_of G) +* f & the_Target_of G2 = (the_Target_of G) +* f )thus
dom f = E
by A2, A3, FUNCT_4:def 1;
( rng f = V1 \/ V2 & the_Source_of G2 = (the_Source_of G) +* f & the_Target_of G2 = (the_Target_of G) +* f )thus
rng f = V1 \/ V2
by A2, A3, A6, NECKLACE:6;
( the_Source_of G2 = (the_Source_of G) +* f & the_Target_of G2 = (the_Target_of G) +* f )thus
the_Source_of G2 = (the_Source_of G) +* f
by A2, A3, FUNCT_4:14;
the_Target_of G2 = (the_Target_of G) +* fthus
the_Target_of G2 = (the_Target_of G) +* f
by A2, A3, FUNCT_4:14;
verum end;
hence
G2 is addLoops of G,V1 \/ V2
by A4, A5, Def5; verum