set V = {0 ,1};
set E = {0 };
set S = 0 .--> 0 ;
set T = 0 .--> 1;
A1:
dom (0 .--> 1) = {0 }
by FUNCOP_1:19;
reconsider T = 0 .--> 1 as Function of {0 },{0 ,1} by A1, A2, FUNCT_2:5;
dom (0 .--> 0 ) = {0 }
by FUNCOP_1:19;
then reconsider S = 0 .--> 0 as Function of {0 },{0 ,1} by A3, 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 complete )
the_Source_of (createGraph {0 ,1},{0 },S,T) = S
by GLIB_000:8;
then A4:
(the_Source_of (createGraph {0 ,1},{0 },S,T)) . 0 = 0
by FUNCOP_1:87;
A5:
the_Edges_of (createGraph {0 ,1},{0 },S,T) = {0 }
by GLIB_000:8;
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 A6:
e1 Joins v1,
v2,
createGraph {0 ,1},
{0 },
S,
T
and A7:
e2 Joins v1,
v2,
createGraph {0 ,1},
{0 },
S,
T
;
not e1 <> e2
e1 in {0 }
by A5, A6, GLIB_000:def 15;
then A8:
e1 = 0
by TARSKI:def 1;
assume A9:
e1 <> e2
;
contradiction
e2 in {0 }
by A5, A7, GLIB_000:def 15;
hence
contradiction
by A9, A8, TARSKI:def 1;
verum end;
then A10:
createGraph {0 ,1},{0 },S,T is non-multi
by GLIB_000:def 22;
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 complete )
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;
0 in the_Edges_of (createGraph {0 ,1},{0 },S,T)
by A5, TARSKI:def 1;
then A13:
0 Joins 0 ,1, createGraph {0 ,1},{0 },S,T
by A4, A12, GLIB_000:def 15;
now let v,
e be
set ;
not e Joins v,v, createGraph {0 ,1},{0 },S,Tassume A14:
e Joins v,
v,
createGraph {0 ,1},
{0 },
S,
T
;
contradictionreconsider v =
v as
Vertex of
(createGraph {0 ,1},{0 },S,T) by A14, GLIB_000:16;
e in the_Edges_of (createGraph {0 ,1},{0 },S,T)
by A14, GLIB_000:def 15;
then
e Joins 0 ,1,
createGraph {0 ,1},
{0 },
S,
T
by A5, A13, TARSKI:def 1;
then
( (
0 = v & 1
= v ) or (
0 = v & 1
= v ) )
by A14, GLIB_000:18;
hence
contradiction
;
verum end;
then
createGraph {0 ,1},{0 },S,T is loopless
by GLIB_000:21;
hence
createGraph {0 ,1},{0 },S,T is simple
by A10; createGraph {0 ,1},{0 },S,T is complete
now let u,
v be
Vertex of
(createGraph {0 ,1},{0 },S,T);
( u <> v implies b1,b2 are_adjacent )assume A15:
u <> v
;
b1,b2 are_adjacent per cases
( u = 0 or u = 1 )
by A11, TARSKI:def 2;
suppose A16:
u = 0
;
b1,b2 are_adjacent A17:
0 in the_Edges_of (createGraph {0 ,1},{0 },S,T)
by A5, TARSKI:def 1;
v = 1
by A11, A15, A16, TARSKI:def 2;
then
0 Joins u,
v,
createGraph {0 ,1},
{0 },
S,
T
by A4, A12, A16, A17, GLIB_000:def 15;
hence
u,
v are_adjacent
by Def3;
verum end; suppose A18:
u = 1
;
b1,b2 are_adjacent A19:
0 in the_Edges_of (createGraph {0 ,1},{0 },S,T)
by A5, TARSKI:def 1;
v = 0
by A11, A15, A18, TARSKI:def 2;
then
0 Joins v,
u,
createGraph {0 ,1},
{0 },
S,
T
by A4, A12, A18, A19, GLIB_000:def 15;
hence
u,
v are_adjacent
by Def3;
verum end; end; end;
hence
createGraph {0 ,1},{0 },S,T is complete
by Def6; verum