now
per cases ( ( V is non empty Subset of (the_Vertices_of G) & E c= G .edgesBetween V ) or not V is non empty Subset of (the_Vertices_of G) or not E c= G .edgesBetween V ) ;
suppose A1: ( V is non empty Subset of (the_Vertices_of G) & E c= G .edgesBetween V ) ; :: thesis: ex GG being [ELabeled] inducedSubgraph of G,V,E st GG is elabel-inheriting
consider X being [ELabeled] inducedSubgraph of G,V,E;
set EL = (the_ELabel_of G) | (the_Edges_of X);
reconsider EL9 = (the_ELabel_of G) | (the_Edges_of X) as PartFunc of (dom ((the_ELabel_of G) | (the_Edges_of X))),(rng ((the_ELabel_of G) | (the_Edges_of X))) by RELSET_1:11;
reconsider EL9 = EL9 as PartFunc of (the_Edges_of X),(rng ((the_ELabel_of G) | (the_Edges_of X))) by RELAT_1:87, RELSET_1:13;
set GG = X .set ELabelSelector ,EL9;
A2: X .set ELabelSelector ,EL9 == X by Lm3;
then X .set ELabelSelector ,EL9 is Subgraph of X by GLIB_000:90;
then reconsider GG = X .set ELabelSelector ,EL9 as Subgraph of G by GLIB_000:46;
A3: the_Vertices_of GG = the_Vertices_of X by A2, GLIB_000:def 36
.= V by A1, GLIB_000:def 39 ;
the_Edges_of GG = the_Edges_of X by A2, GLIB_000:def 36
.= E by A1, GLIB_000:def 39 ;
then reconsider GG = GG as [ELabeled] inducedSubgraph of G,V,E by A1, A3, GLIB_000:def 39;
take GG = GG; :: thesis: GG is elabel-inheriting
the_ELabel_of GG = (the_ELabel_of G) | (the_Edges_of X) by GLIB_000:11
.= (the_ELabel_of G) | (the_Edges_of GG) by A2, GLIB_000:def 36 ;
hence GG is elabel-inheriting by Def11; :: thesis: verum
end;
end;
end;
hence ex b1 being [ELabeled] inducedSubgraph of G,V,E st b1 is elabel-inheriting ; :: thesis: verum