let G be non-Dmulti _Graph; ex F being PGraphMapping of G, createGraph ((the_Vertices_of G),(VertexDomRel G)) st
( F is Disomorphism & F _V = id (the_Vertices_of G) & ( for e being object st e in the_Edges_of G holds
(F _E) . e = [((the_Source_of G) . e),((the_Target_of G) . e)] ) )
set G9 = createGraph ((the_Vertices_of G),(VertexDomRel G));
reconsider f = id (the_Vertices_of G) as PartFunc of (the_Vertices_of G),(the_Vertices_of (createGraph ((the_Vertices_of G),(VertexDomRel G)))) ;
deffunc H1( object ) -> object = [((the_Source_of G) . $1),((the_Target_of G) . $1)];
consider g being Function such that
A1:
dom g = the_Edges_of G
and
A2:
for x being object st x in the_Edges_of G holds
g . x = H1(x)
from FUNCT_1:sch 3();
now for y being object holds
( ( y in rng g implies y in the_Edges_of (createGraph ((the_Vertices_of G),(VertexDomRel G))) ) & ( y in the_Edges_of (createGraph ((the_Vertices_of G),(VertexDomRel G))) implies y in rng g ) )let y be
object ;
( ( y in rng g implies y in the_Edges_of (createGraph ((the_Vertices_of G),(VertexDomRel G))) ) & ( y in the_Edges_of (createGraph ((the_Vertices_of G),(VertexDomRel G))) implies y in rng g ) )hereby ( y in the_Edges_of (createGraph ((the_Vertices_of G),(VertexDomRel G))) implies y in rng g )
assume
y in rng g
;
y in the_Edges_of (createGraph ((the_Vertices_of G),(VertexDomRel G)))then consider x being
object such that A3:
(
x in dom g &
g . x = y )
by FUNCT_1:def 3;
A4:
y = [((the_Source_of G) . x),((the_Target_of G) . x)]
by A1, A2, A3;
x DJoins (the_Source_of G) . x,
(the_Target_of G) . x,
G
by A1, A3, GLIB_000:def 14;
then
y in VertexDomRel G
by A4, Th1;
hence
y in the_Edges_of (createGraph ((the_Vertices_of G),(VertexDomRel G)))
;
verum
end; assume
y in the_Edges_of (createGraph ((the_Vertices_of G),(VertexDomRel G)))
;
y in rng gthen A5:
y in VertexDomRel G
;
then consider v,
w being
object such that A6:
y = [v,w]
by RELAT_1:def 1;
consider e being
object such that A7:
e DJoins v,
w,
G
by A5, A6, Th1;
A8:
(
e in the_Edges_of G &
(the_Source_of G) . e = v &
(the_Target_of G) . e = w )
by A7, GLIB_000:def 14;
then
g . e = y
by A2, A6;
hence
y in rng g
by A1, A8, FUNCT_1:3;
verum end;
then A9:
rng g = the_Edges_of (createGraph ((the_Vertices_of G),(VertexDomRel G)))
by TARSKI:2;
then reconsider g = g as PartFunc of (the_Edges_of G),(the_Edges_of (createGraph ((the_Vertices_of G),(VertexDomRel G)))) by A1, RELSET_1:4;
now ( ( for e being object st e in dom g holds
( (the_Source_of G) . e in dom f & (the_Target_of G) . e in dom f ) ) & ( for e, v, w being object st e in dom g & v in dom f & w in dom f & e DJoins v,w,G holds
g . e DJoins f . v,f . w, createGraph ((the_Vertices_of G),(VertexDomRel G)) ) )thus
for
e being
object st
e in dom g holds
(
(the_Source_of G) . e in dom f &
(the_Target_of G) . e in dom f )
by FUNCT_2:5;
for e, v, w being object st e in dom g & v in dom f & w in dom f & e DJoins v,w,G holds
g . e DJoins f . v,f . w, createGraph ((the_Vertices_of G),(VertexDomRel G))let e,
v,
w be
object ;
( e in dom g & v in dom f & w in dom f & e DJoins v,w,G implies g . e DJoins f . v,f . w, createGraph ((the_Vertices_of G),(VertexDomRel G)) )assume A10:
(
e in dom g &
v in dom f &
w in dom f &
e DJoins v,
w,
G )
;
g . e DJoins f . v,f . w, createGraph ((the_Vertices_of G),(VertexDomRel G))then A11:
(
(the_Source_of G) . e = v &
(the_Target_of G) . e = w )
by GLIB_000:def 14;
A12:
g . e = [v,w]
by A2, A10, A11;
g . e in rng g
by A10, FUNCT_1:3;
then
g . e in the_Edges_of (createGraph ((the_Vertices_of G),(VertexDomRel G)))
;
then
g . e in VertexDomRel G
;
then
g . e DJoins v,
w,
createGraph (
(the_Vertices_of G),
(VertexDomRel G))
by A12, Th63;
then
g . e DJoins f . v,
w,
createGraph (
(the_Vertices_of G),
(VertexDomRel G))
by A10, FUNCT_1:18;
hence
g . e DJoins f . v,
f . w,
createGraph (
(the_Vertices_of G),
(VertexDomRel G))
by A10, FUNCT_1:18;
verum end;
then reconsider F = [f,g] as directed PGraphMapping of G, createGraph ((the_Vertices_of G),(VertexDomRel G)) by GLIB_010:30;
take
F
; ( F is Disomorphism & F _V = id (the_Vertices_of G) & ( for e being object st e in the_Edges_of G holds
(F _E) . e = [((the_Source_of G) . e),((the_Target_of G) . e)] ) )
then A14:
g is one-to-one
by FUNCT_1:def 4;
( f is one-to-one & F _V = f & F _E = g )
;
then A15:
F is one-to-one
by A14, GLIB_010:def 13;
A16:
( dom f = the_Vertices_of G & rng f = the_Vertices_of (createGraph ((the_Vertices_of G),(VertexDomRel G))) )
;
( F _V = f & F _E = g )
;
then A17:
( F is total & F is onto )
by A1, A9, A16, GLIB_010:def 11, GLIB_010:def 12;
thus
F is Disomorphism
by A15, A17; ( F _V = id (the_Vertices_of G) & ( for e being object st e in the_Edges_of G holds
(F _E) . e = [((the_Source_of G) . e),((the_Target_of G) . e)] ) )
thus
F _V = id (the_Vertices_of G)
; for e being object st e in the_Edges_of G holds
(F _E) . e = [((the_Source_of G) . e),((the_Target_of G) . e)]
let e be object ; ( e in the_Edges_of G implies (F _E) . e = [((the_Source_of G) . e),((the_Target_of G) . e)] )
assume
e in the_Edges_of G
; (F _E) . e = [((the_Source_of G) . e),((the_Target_of G) . e)]
hence
(F _E) . e = [((the_Source_of G) . e),((the_Target_of G) . e)]
by A2; verum