let G be _Graph; for V being non empty Subset of (the_Vertices_of G)
for H being inducedSubgraph of G,V
for E being RepDEdgeSelection of G holds E /\ (G .edgesBetween V) is RepDEdgeSelection of H
let V be non empty Subset of (the_Vertices_of G); for H being inducedSubgraph of G,V
for E being RepDEdgeSelection of G holds E /\ (G .edgesBetween V) is RepDEdgeSelection of H
let H be inducedSubgraph of G,V; for E being RepDEdgeSelection of G holds E /\ (G .edgesBetween V) is RepDEdgeSelection of H
let E be RepDEdgeSelection of G; E /\ (G .edgesBetween V) is RepDEdgeSelection of H
G .edgesBetween V = the_Edges_of H
by GLIB_000:def 37;
then reconsider E9 = E /\ (G .edgesBetween V) as Subset of (the_Edges_of H) by XBOOLE_1:17;
now for v, w, e0 being object st e0 DJoins v,w,H holds
ex e being object st
( e DJoins v,w,H & e in E9 & ( for e9 being object st e9 DJoins v,w,H & e9 in E9 holds
e9 = e ) )let v,
w,
e0 be
object ;
( e0 DJoins v,w,H implies ex e being object st
( e DJoins v,w,H & e in E9 & ( for e9 being object st e9 DJoins v,w,H & e9 in E9 holds
e9 = e ) ) )A1:
(
v is
set &
w is
set )
by TARSKI:1;
assume A2:
e0 DJoins v,
w,
H
;
ex e being object st
( e DJoins v,w,H & e in E9 & ( for e9 being object st e9 DJoins v,w,H & e9 in E9 holds
e9 = e ) )then
e0 DJoins v,
w,
G
by A1, GLIB_000:72;
then consider e being
object such that A3:
(
e DJoins v,
w,
G &
e in E )
and A4:
for
e9 being
object st
e9 DJoins v,
w,
G &
e9 in E holds
e9 = e
by GLIB_009:def 6;
take e =
e;
( e DJoins v,w,H & e in E9 & ( for e9 being object st e9 DJoins v,w,H & e9 in E9 holds
e9 = e ) )
e0 Joins v,
w,
H
by A2, GLIB_000:16;
then
(
v in the_Vertices_of H &
w in the_Vertices_of H )
by GLIB_000:13;
then A5:
(
v in V &
w in V )
by GLIB_000:def 37;
e Joins v,
w,
G
by A3, GLIB_000:16;
then A6:
e in G .edgesBetween V
by A5, GLIB_000:32;
then
e in the_Edges_of H
by GLIB_000:def 37;
hence
e DJoins v,
w,
H
by A1, A3, GLIB_000:73;
( e in E9 & ( for e9 being object st e9 DJoins v,w,H & e9 in E9 holds
e9 = e ) )thus
e in E9
by A3, A6, XBOOLE_0:def 4;
for e9 being object st e9 DJoins v,w,H & e9 in E9 holds
e9 = elet e9 be
object ;
( e9 DJoins v,w,H & e9 in E9 implies e9 = e )assume
(
e9 DJoins v,
w,
H &
e9 in E9 )
;
e9 = ethen
(
e9 DJoins v,
w,
G &
e9 in E )
by A1, GLIB_000:72, XBOOLE_0:def 4;
hence
e9 = e
by A4;
verum end;
hence
E /\ (G .edgesBetween V) is RepDEdgeSelection of H
by GLIB_009:def 6; verum