set R = the InternalRel of Q;
set IT = { x where x is Element of Q : ex f being continuous Function of P,Q st
( f in F & x = f . p ) } ;
for x being set st x in { x where x is Element of Q : ex f being continuous Function of P,Q st
( f in F & x = f . p ) } holds
x in the carrier of Q
then reconsider IT = { x where x is Element of Q : ex f being continuous Function of P,Q st
( f in F & x = f . p ) } as Subset of Q by TARSKI:def 3;
for x, y being set st x in IT & y in IT & x <> y & not [x,y] in the InternalRel of Q holds
[y,x] in the InternalRel of Q
proof
let x,
y be
set ;
( x in IT & y in IT & x <> y & not [x,y] in the InternalRel of Q implies [y,x] in the InternalRel of Q )
assume B1:
(
x in IT &
y in IT &
x <> y )
;
( [x,y] in the InternalRel of Q or [y,x] in the InternalRel of Q )
then consider a being
Element of
Q such that B2:
(
x = a & ex
f being
continuous Function of
P,
Q st
(
f in F &
a = f . p ) )
;
consider f being
continuous Function of
P,
Q such that B3:
(
f in F &
a = f . p )
by B2;
consider b being
Element of
Q such that B5:
(
y = b & ex
g being
continuous Function of
P,
Q st
(
g in F &
b = g . p ) )
by B1;
consider g being
continuous Function of
P,
Q such that B6:
(
g in F &
b = g . p )
by B5;
set S = the
InternalRel of
(ConPoset (P,Q));
B9:
the
InternalRel of
(ConPoset (P,Q)) is_strongly_connected_in F
by ORDERS_2:def 11;
end;
then A1:
the InternalRel of Q is_connected_in IT
by RELAT_2:def 6;
for x being set st x in IT holds
[x,x] in the InternalRel of Q
then
the InternalRel of Q is_reflexive_in IT
by RELAT_2:def 1;
then
the InternalRel of Q is_strongly_connected_in IT
by A1, ORDERS_1:92;
then reconsider IT = IT as Chain of Q by ORDERS_2:def 11;
consider a being set such that
A2:
a in F
by XBOOLE_0:7;
a in ConFuncs (P,Q)
by A2;
then consider b being Element of Funcs ( the carrier of P, the carrier of Q) such that
A3:
( a = b & ex f being continuous Function of P,Q st f = b )
;
consider f being continuous Function of P,Q such that
A4:
f = b
by A3;
reconsider c = f . p as Element of Q ;
c in IT
by A2, A3, A4;
hence
{ x where x is Element of Q : ex f being continuous Function of P,Q st
( f in F & x = f . p ) } is non empty Chain of Q
; verum