set V = {0,1};
set E = {0};
set S = 0 .--> 0;
set T = 0 .--> 1;
A7:
dom (0 .--> 1) = {0}
by FUNCOP_1:19;
reconsider T = 0 .--> 1 as Function of {0},{0,1} by A7, A8, FUNCT_2:5;
dom (0 .--> 0) = {0}
by FUNCOP_1:19;
then reconsider S = 0 .--> 0 as Function of {0},{0,1} by A9, FUNCT_2:5;
set G = createGraph ({0,1},{0},S,T);
take
createGraph ({0,1},{0},S,T)
; ( not createGraph ({0,1},{0},S,T) is trivial & createGraph ({0,1},{0},S,T) is finite & createGraph ({0,1},{0},S,T) is simple & createGraph ({0,1},{0},S,T) is chordal )
the_Source_of (createGraph ({0,1},{0},S,T)) = S
by GLIB_000:8;
then A10:
(the_Source_of (createGraph ({0,1},{0},S,T))) . 0 = 0
by FUNCOP_1:87;
A11:
the_Vertices_of (createGraph ({0,1},{0},S,T)) = {0,1}
by GLIB_000:8;
hence
( not createGraph ({0,1},{0},S,T) is trivial & createGraph ({0,1},{0},S,T) is finite )
by GLIB_000:def 21; ( createGraph ({0,1},{0},S,T) is simple & createGraph ({0,1},{0},S,T) is chordal )
the_Target_of (createGraph ({0,1},{0},S,T)) = T
by GLIB_000:8;
then A12:
(the_Target_of (createGraph ({0,1},{0},S,T))) . 0 = 1
by FUNCOP_1:87;
A13:
the_Edges_of (createGraph ({0,1},{0},S,T)) = {0}
by GLIB_000:8;
then
0 in the_Edges_of (createGraph ({0,1},{0},S,T))
by TARSKI:def 1;
then A14:
0 Joins 0 ,1, createGraph ({0,1},{0},S,T)
by A10, A12, GLIB_000:def 15;
now let v,
e be
set ;
not e Joins v,v, createGraph ({0,1},{0},S,T)assume A15:
e Joins v,
v,
createGraph (
{0,1},
{0},
S,
T)
;
contradictionreconsider v =
v as
Vertex of
(createGraph ({0,1},{0},S,T)) by A15, GLIB_000:16;
e in the_Edges_of (createGraph ({0,1},{0},S,T))
by A15, GLIB_000:def 15;
then
e Joins 0 ,1,
createGraph (
{0,1},
{0},
S,
T)
by A13, A14, TARSKI:def 1;
then
( (
0 = v & 1
= v ) or (
0 = v & 1
= v ) )
by A15, GLIB_000:18;
hence
contradiction
;
verum end;
then A16:
createGraph ({0,1},{0},S,T) is loopless
by GLIB_000:21;
now let e1,
e2,
v1,
v2 be
set ;
( e1 Joins v1,v2, createGraph ({0,1},{0},S,T) & e2 Joins v1,v2, createGraph ({0,1},{0},S,T) implies not e1 <> e2 )assume that A17:
e1 Joins v1,
v2,
createGraph (
{0,1},
{0},
S,
T)
and A18:
e2 Joins v1,
v2,
createGraph (
{0,1},
{0},
S,
T)
;
not e1 <> e2
e1 in {0}
by A13, A17, GLIB_000:def 15;
then A19:
e1 = 0
by TARSKI:def 1;
assume A20:
e1 <> e2
;
contradiction
e2 in {0}
by A13, A18, GLIB_000:def 15;
hence
contradiction
by A20, A19, TARSKI:def 1;
verum end;
then
createGraph ({0,1},{0},S,T) is non-multi
by GLIB_000:def 22;
hence
createGraph ({0,1},{0},S,T) is simple
by A16; createGraph ({0,1},{0},S,T) is chordal
card (the_Vertices_of (createGraph ({0,1},{0},S,T))) = 2
by A11, CARD_2:76;
hence
createGraph ({0,1},{0},S,T) is chordal
by Th96; verum