let G be _Graph; ( G is self-DLcomplementary implies ( not G is _trivial & not G is self-Lcomplementary & not G is self-Dcomplementary & not G is self-complementary ) )
assume A11:
G is self-DLcomplementary
; ( not G is _trivial & not G is self-Lcomplementary & not G is self-Dcomplementary & not G is self-complementary )
hence A12:
not G is _trivial
; ( not G is self-Lcomplementary & not G is self-Dcomplementary & not G is self-complementary )
thus
not G is self-Lcomplementary
( not G is self-Dcomplementary & not G is self-complementary )proof
assume A13:
G is
self-Lcomplementary
;
contradiction
set H1 = the
DLGraphComplement of
G;
set H2 = the
LGraphComplement of
G;
the
DLGraphComplement of
G is
G -Disomorphic
by A11;
then consider F1 being
PGraphMapping of
G, the
DLGraphComplement of
G such that A14:
F1 is
Disomorphism
by GLIB_010:def 24;
the
LGraphComplement of
G is
G -isomorphic
by A13;
then consider F2 being
PGraphMapping of
G, the
LGraphComplement of
G such that A15:
F2 is
isomorphism
by GLIB_010:def 23;
now for v1, v2 being Vertex of G st v1 <> v2 holds
v1,v2 are_adjacent let v1,
v2 be
Vertex of
G;
( v1 <> v2 implies v1,v2 are_adjacent )assume A16:
v1 <> v2
;
v1,v2 are_adjacent assume A17:
not
v1,
v2 are_adjacent
;
contradiction
for
e being
object holds not
e DJoins v1,
v2,
G
then consider e1 being
object such that A19:
e1 DJoins v1,
v2, the
DLGraphComplement of
G
by Def6;
for
e being
object holds not
e DJoins v2,
v1,
G
then consider e2 being
object such that A21:
e2 DJoins v2,
v1, the
DLGraphComplement of
G
by Def6;
A22:
(
e1 Joins v1,
v2, the
DLGraphComplement of
G &
e2 Joins v1,
v2, the
DLGraphComplement of
G )
by A19, A21, GLIB_000:16;
the
DLGraphComplement of
G is
non-multi
by A13, A14, GLIB_010:89;
then
e1 = e2
by A22, GLIB_000:def 20;
hence
contradiction
by A16, A19, A21, GLIB_000:125;
verum end;
then A23:
G is
complete
by CHORD:def 6;
then A24:
the_Edges_of the
LGraphComplement of
G = the
LGraphComplement of
G .loops()
by Th75;
consider v1,
v2 being
Vertex of
G such that A25:
v1 <> v2
by A12, GLIB_000:21;
consider e being
object such that A26:
e Joins v1,
v2,
G
by A23, A25, CHORD:def 6, CHORD:def 3;
(
dom (F2 _E) = the_Edges_of G &
dom (F2 _V) = the_Vertices_of G )
by A15, GLIB_010:def 11;
then A27:
(
e in dom (F2 _E) &
v1 in dom (F2 _V) &
v2 in dom (F2 _V) )
by A26, GLIB_000:def 13;
then A28:
(F2 _E) . e Joins (F2 _V) . v1,
(F2 _V) . v2, the
LGraphComplement of
G
by A26, GLIB_010:4;
(F2 _V) . v1 <> (F2 _V) . v2
by A15, A25, A27, FUNCT_1:def 4;
then
not
(F2 _E) . e in the
LGraphComplement of
G .loops()
by A28, GLIB_009:46;
hence
contradiction
by A24, A28, GLIB_000:def 13;
verum
end;
thus
( not G is self-Dcomplementary & not G is self-complementary )
by A11; verum