let G2 be _Graph; for v being object
for V being Subset of (the_Vertices_of G2)
for G1 being addAdjVertexAll of G2,v,V
for g2 being EColoring of G2
for h being Function st not v in the_Vertices_of G2 & dom h = G1 .edgesBetween (V,{v}) holds
g2 +* h is EColoring of G1
let v be object ; for V being Subset of (the_Vertices_of G2)
for G1 being addAdjVertexAll of G2,v,V
for g2 being EColoring of G2
for h being Function st not v in the_Vertices_of G2 & dom h = G1 .edgesBetween (V,{v}) holds
g2 +* h is EColoring of G1
let V be Subset of (the_Vertices_of G2); for G1 being addAdjVertexAll of G2,v,V
for g2 being EColoring of G2
for h being Function st not v in the_Vertices_of G2 & dom h = G1 .edgesBetween (V,{v}) holds
g2 +* h is EColoring of G1
let G1 be addAdjVertexAll of G2,v,V; for g2 being EColoring of G2
for h being Function st not v in the_Vertices_of G2 & dom h = G1 .edgesBetween (V,{v}) holds
g2 +* h is EColoring of G1
let g2 be EColoring of G2; for h being Function st not v in the_Vertices_of G2 & dom h = G1 .edgesBetween (V,{v}) holds
g2 +* h is EColoring of G1
let h be Function; ( not v in the_Vertices_of G2 & dom h = G1 .edgesBetween (V,{v}) implies g2 +* h is EColoring of G1 )
set E = dom h;
assume A1:
( not v in the_Vertices_of G2 & dom h = G1 .edgesBetween (V,{v}) )
; g2 +* h is EColoring of G1
dom (g2 +* h) =
(dom g2) \/ (dom h)
by FUNCT_4:def 1
.=
(the_Edges_of G2) \/ (dom h)
by PARTFUN1:def 2
.=
the_Edges_of G1
by A1, GLIB_007:59
;
hence
g2 +* h is EColoring of G1
by RELAT_1:def 18, PARTFUN1:def 2; verum