now ( VLabelSelector in dom (G2 .set (VLabelSelector,(the_VLabel_of G1))) & ex f being Function st
( (G2 .set (VLabelSelector,(the_VLabel_of G1))) . VLabelSelector = f & dom f c= the_Vertices_of (G2 .set (VLabelSelector,(the_VLabel_of G1))) ) )set G3 =
G2 .set (
VLabelSelector,
(the_VLabel_of G1));
VLabelSelector in {VLabelSelector}
by TARSKI:def 1;
then
VLabelSelector in (dom G2) \/ {VLabelSelector}
by XBOOLE_0:def 3;
hence
VLabelSelector in dom (G2 .set (VLabelSelector,(the_VLabel_of G1)))
by GLIB_000:7;
ex f being Function st
( (G2 .set (VLabelSelector,(the_VLabel_of G1))) . VLabelSelector = f & dom f c= the_Vertices_of (G2 .set (VLabelSelector,(the_VLabel_of G1))) )consider f being
Function such that A1:
(
G1 . VLabelSelector = f &
dom f c= the_Vertices_of G1 )
by GLIB_003:def 6;
G2 == G2 .set (
VLabelSelector,
(the_VLabel_of G1))
by GLIB_003:7;
then
the_Vertices_of G2 = the_Vertices_of (G2 .set (VLabelSelector,(the_VLabel_of G1)))
by GLIB_000:def 34;
then A2:
the_Vertices_of G1 = the_Vertices_of (G2 .set (VLabelSelector,(the_VLabel_of G1)))
by GLIB_007:4;
take f =
f;
( (G2 .set (VLabelSelector,(the_VLabel_of G1))) . VLabelSelector = f & dom f c= the_Vertices_of (G2 .set (VLabelSelector,(the_VLabel_of G1))) )thus (G2 .set (VLabelSelector,(the_VLabel_of G1))) . VLabelSelector =
the_VLabel_of G1
by GLIB_000:8
.=
f
by A1, GLIB_003:def 9
;
dom f c= the_Vertices_of (G2 .set (VLabelSelector,(the_VLabel_of G1)))thus
dom f c= the_Vertices_of (G2 .set (VLabelSelector,(the_VLabel_of G1)))
by A1, A2;
verum end;
hence
G2 .set (VLabelSelector,(the_VLabel_of G1)) is [VLabeled]
by GLIB_003:def 6; verum