let G be _Graph; :: thesis: for V being non empty one-to-one ManySortedSet of the_Vertices_of G
for E being one-to-one ManySortedSet of the_Edges_of G
for e, v, w being object st e DJoins v,w,G holds
E . e DJoins V . v,V . w, replaceVerticesEdges (V,E)

let V be non empty one-to-one ManySortedSet of the_Vertices_of G; :: thesis: for E being one-to-one ManySortedSet of the_Edges_of G
for e, v, w being object st e DJoins v,w,G holds
E . e DJoins V . v,V . w, replaceVerticesEdges (V,E)

let E be one-to-one ManySortedSet of the_Edges_of G; :: thesis: for e, v, w being object st e DJoins v,w,G holds
E . e DJoins V . v,V . w, replaceVerticesEdges (V,E)

A1: ( dom V = the_Vertices_of G & dom E = the_Edges_of G ) by PARTFUN1:def 2;
let e, v, w be object ; :: thesis: ( e DJoins v,w,G implies E . e DJoins V . v,V . w, replaceVerticesEdges (V,E) )
assume A2: e DJoins v,w,G ; :: thesis: E . e DJoins V . v,V . w, replaceVerticesEdges (V,E)
then A3: e in the_Edges_of G by GLIB_000:def 14;
then A4: ( e in dom (the_Source_of G) & e in dom (the_Target_of G) ) by FUNCT_2:def 1;
E . e in rng E by A1, A3, FUNCT_1:3;
then A5: ( E . e in dom (E ") & E . e in the_Edges_of (replaceVerticesEdges (V,E)) ) by Th1, FUNCT_1:33;
A6: V . v = V . ((the_Source_of G) . e) by A2, GLIB_000:def 14
.= (V * (the_Source_of G)) . e by A4, FUNCT_1:13
.= (V * (the_Source_of G)) . ((E ") . (E . e)) by A1, A3, FUNCT_1:34
.= ((V * (the_Source_of G)) * (E ")) . (E . e) by A5, FUNCT_1:13
.= (the_Source_of (replaceVerticesEdges (V,E))) . (E . e) by Th1 ;
V . w = V . ((the_Target_of G) . e) by A2, GLIB_000:def 14
.= (V * (the_Target_of G)) . e by A4, FUNCT_1:13
.= (V * (the_Target_of G)) . ((E ") . (E . e)) by A1, A3, FUNCT_1:34
.= ((V * (the_Target_of G)) * (E ")) . (E . e) by A5, FUNCT_1:13
.= (the_Target_of (replaceVerticesEdges (V,E))) . (E . e) by Th1 ;
hence E . e DJoins V . v,V . w, replaceVerticesEdges (V,E) by A5, A6, GLIB_000:def 14; :: thesis: verum