let G be _Graph; :: thesis: for H being removeLoops of G holds H is GraphUnion of G .allSpanningForests()
let H be removeLoops of G; :: thesis: H is GraphUnion of G .allSpanningForests()
set G9 = the GraphUnion of G .allSpanningForests() ;
reconsider G8 = G as GraphUnion of G .allSG() by Th35;
set H9 = the GraphUnion of {H};
now :: thesis: ( the GraphUnion of G .allSpanningForests() is Subgraph of G8 & the_Vertices_of H c= the_Vertices_of the GraphUnion of G .allSpanningForests() & the_Edges_of H c= the_Edges_of the GraphUnion of G .allSpanningForests() )
thus the GraphUnion of G .allSpanningForests() is Subgraph of G8 by GLIBPRE1:119; :: thesis: ( the_Vertices_of H c= the_Vertices_of the GraphUnion of G .allSpanningForests() & the_Edges_of H c= the_Edges_of the GraphUnion of G .allSpanningForests() )
now :: thesis: for x being object st x in the_Vertices_of H holds
x in the_Vertices_of the GraphUnion of G .allSpanningForests()
end;
hence the_Vertices_of H c= the_Vertices_of the GraphUnion of G .allSpanningForests() by TARSKI:def 3; :: thesis: the_Edges_of H c= the_Edges_of the GraphUnion of G .allSpanningForests()
now :: thesis: for x being object st x in the_Edges_of H holds
x in the_Edges_of the GraphUnion of G .allSpanningForests()
end;
hence the_Edges_of H c= the_Edges_of the GraphUnion of G .allSpanningForests() by TARSKI:def 3; :: thesis: verum
end;
then A3: H is Subgraph of the GraphUnion of G .allSpanningForests() by GLIB_000:44;
now :: thesis: for H2 being Element of G .allSpanningForests() ex H1 being Element of {H} st H2 is Subgraph of H1
let H2 be Element of G .allSpanningForests() ; :: thesis: ex H1 being Element of {H} st H2 is Subgraph of H1
reconsider H1 = H as Element of {H} by TARSKI:def 1;
take H1 = H1; :: thesis: H2 is Subgraph of H1
H .allSpanningForests() = G .allSpanningForests() by Th110;
hence H2 is Subgraph of H1 by Th102; :: thesis: verum
end;
then the GraphUnion of G .allSpanningForests() is Subgraph of the GraphUnion of {H} by GLIBPRE1:118;
then the GraphUnion of G .allSpanningForests() is Subgraph of H by GLIB_000:91, GLIB_014:24;
hence H is GraphUnion of G .allSpanningForests() by A3, GLIB_000:87, GLIB_014:22; :: thesis: verum