let X, Y be non empty TopSpace; for S being Scott TopAugmentation of InclPoset the topology of Y
for f being Function of X,S st *graph f is open Subset of [:X,Y:] holds
f is continuous
let S be Scott TopAugmentation of InclPoset the topology of Y; for f being Function of X,S st *graph f is open Subset of [:X,Y:] holds
f is continuous
let f be Function of X,S; ( *graph f is open Subset of [:X,Y:] implies f is continuous )
A1:
RelStr(# the carrier of S,the InternalRel of S #) = RelStr(# the carrier of (InclPoset the topology of Y),the InternalRel of (InclPoset the topology of Y) #)
by YELLOW_9:def 4;
A2:
dom f = the carrier of X
by FUNCT_2:def 1;
assume
*graph f is open Subset of [:X,Y:]
; f is continuous
then consider AA being Subset-Family of [:X,Y:] such that
A3:
*graph f = union AA
and
A4:
for e being set st e in AA holds
ex X1 being Subset of X ex Y1 being Subset of Y st
( e = [:X1,Y1:] & X1 is open & Y1 is open )
by BORSUK_1:45;
A5:
the carrier of (InclPoset the topology of Y) = the topology of Y
by YELLOW_1:1;
A6:
now let P be
Subset of
S;
( P is open implies f " P is open )assume A7:
P is
open
;
f " P is open now let x be
set ;
( ( x in f " P implies ex Q being Subset of X st
( Q is open & Q c= f " P & x in Q ) ) & ( ex Q being Subset of X st
( Q is open & Q c= f " P & x in Q ) implies x in f " P ) )hereby ( ex Q being Subset of X st
( Q is open & Q c= f " P & x in Q ) implies x in f " P )
defpred S1[
set ,
set ]
means (
x in $2
`1 & $1
in $2
`2 &
[:($2 `1 ),($2 `2 ):] c= *graph f );
assume A8:
x in f " P
;
ex Q being Subset of X st
( Q is open & Q c= f " P & x in Q )then reconsider y =
x as
Element of
X ;
A9:
now let e be
set ;
( e in f . x implies ex u being set st
( u in [:the topology of X,the topology of Y:] & S1[e,u] ) )assume
e in f . x
;
ex u being set st
( u in [:the topology of X,the topology of Y:] & S1[e,u] )then
[x,e] in *graph f
by A2, A8, Th39;
then consider V being
set such that A10:
[x,e] in V
and A11:
V in AA
by A3, TARSKI:def 4;
consider A being
Subset of
X,
B being
Subset of
Y such that A12:
V = [:A,B:]
and A13:
(
A is
open &
B is
open )
by A4, A11;
reconsider u =
[A,B] as
set ;
take u =
u;
( u in [:the topology of X,the topology of Y:] & S1[e,u] )
(
A in the
topology of
X &
B in the
topology of
Y )
by A13, PRE_TOPC:def 5;
hence
u in [:the topology of X,the topology of Y:]
by ZFMISC_1:106;
S1[e,u]
(
A = u `1 &
B = u `2 )
by MCART_1:7;
hence
S1[
e,
u]
by A3, A10, A11, A12, ZFMISC_1:92, ZFMISC_1:106;
verum end; consider g being
Function such that A14:
(
dom g = f . x &
rng g c= [:the topology of X,the topology of Y:] )
and A15:
for
a being
set st
a in f . x holds
S1[
a,
g . a]
from WELLORD2:sch 1(A9);
set J =
{ (union A) where A is Subset of (proj2 (rng g)) : A is finite } ;
A16:
proj2 (rng g) c= the
topology of
Y
by A14, FUNCT_5:13;
A17:
{ (union A) where A is Subset of (proj2 (rng g)) : A is finite } c= the
topology of
Y
consider A0 being
empty Subset of
(proj2 (rng g));
A0 in { (union A) where A is Subset of (proj2 (rng g)) : A is finite }
by ZFMISC_1:2;
then reconsider J =
{ (union A) where A is Subset of (proj2 (rng g)) : A is finite } as non
empty Subset of
(InclPoset the topology of Y) by A17, YELLOW_1:1;
J is
directed
then reconsider J9 =
J as non
empty directed Subset of
S by A1, WAYBEL_0:3;
A25:
proj2 (rng g) c= bool (f . x)
proof
let z be
set ;
TARSKI:def 3 ( not z in proj2 (rng g) or z in bool (f . x) )
assume
z in proj2 (rng g)
;
z in bool (f . x)
then consider z1 being
set such that A26:
[z1,z] in rng g
by RELAT_1:def 5;
A27:
[z1,z] `1 = z1
by MCART_1:7;
A28:
ex
a being
set st
(
a in dom g &
[z1,z] = g . a )
by A26, FUNCT_1:def 5;
then A29:
x in z1
by A14, A15, A27;
[z1,z] `2 = z
by MCART_1:7;
then A30:
[:z1,z:] c= *graph f
by A14, A15, A28, A27;
z c= f . x
hence
z in bool (f . x)
;
verum
end;
union J = f . y
then
sup J = f . y
by YELLOW_1:22;
then A37:
sup J9 = f . y
by A1, YELLOW_0:17, YELLOW_0:26;
f . y in the
topology of
Y
by A5, A1;
then reconsider W =
f . y as
open Subset of
Y by PRE_TOPC:def 5;
A38:
proj1 (rng g) c= the
topology of
X
by A14, FUNCT_5:13;
defpred S2[
set ,
set ]
means ex
c1 being
set st
(
[c1,$1] = g . $2 &
x in c1 & $2
in $1 & $2
in f . x &
[:c1,$1:] c= *graph f );
f . x in P
by A8, FUNCT_2:46;
then
J meets P
by A7, A37, WAYBEL11:def 1;
then consider a being
set such that A39:
a in J
and A40:
a in P
by XBOOLE_0:3;
reconsider a =
a as
Element of
S by A40;
consider A being
Subset of
(proj2 (rng g)) such that A41:
a = union A
and A42:
A is
finite
by A39;
A43:
now let c be
set ;
( c in A implies ex a being set st
( a in W & S2[c,a] ) )assume
c in A
;
ex a being set st
( a in W & S2[c,a] )then consider c1 being
set such that A44:
[c1,c] in rng g
by RELAT_1:def 5;
consider a being
set such that A45:
a in dom g
and A46:
[c1,c] = g . a
by A44, FUNCT_1:def 5;
take a =
a;
( a in W & S2[c,a] )thus
a in W
by A14, A45;
S2[c,a]A47:
[c1,c] `1 = c1
by MCART_1:7;
then A48:
x in c1
by A14, A15, A45, A46;
A49:
[c1,c] `2 = c
by MCART_1:7;
then
[:c1,c:] c= *graph f
by A14, A15, A45, A46, A47;
hence
S2[
c,
a]
by A14, A15, A45, A46, A49, A48;
verum end; consider hh being
Function such that A50:
(
dom hh = A &
rng hh c= W )
and A51:
for
c being
set st
c in A holds
S2[
c,
hh . c]
from WELLORD2:sch 1(A43);
set B =
proj1 (g .: (rng hh));
g .: (rng hh) c= rng g
by RELAT_1:144;
then
proj1 (g .: (rng hh)) c= proj1 (rng g)
by FUNCT_5:5;
then A52:
proj1 (g .: (rng hh)) c= the
topology of
X
by A38, XBOOLE_1:1;
then reconsider B =
proj1 (g .: (rng hh)) as
Subset-Family of
X by XBOOLE_1:1;
reconsider B =
B as
Subset-Family of
X ;
reconsider Q =
Intersect B as
Subset of
X ;
take Q =
Q;
( Q is open & Q c= f " P & x in Q )
g .: (rng hh) is
finite
by A42, A50, FINSET_1:17, FINSET_1:26;
then
B is
finite
by Th40;
then
Q in FinMeetCl the
topology of
X
by A52, CANTOR_1:def 4;
then
Q in the
topology of
X
by CANTOR_1:5;
hence
Q is
open
by PRE_TOPC:def 5;
( Q c= f " P & x in Q )thus
Q c= f " P
x in Qproof
let z be
set ;
TARSKI:def 3 ( not z in Q or z in f " P )
assume A53:
z in Q
;
z in f " P
then reconsider zz =
z as
Element of
X ;
reconsider fz =
f . zz,
aa =
a as
Element of
(InclPoset the topology of Y) by A1;
a c= f . zz
proof
let p be
set ;
TARSKI:def 3 ( not p in a or p in f . zz )
assume
p in a
;
p in f . zz
then consider q being
set such that A54:
p in q
and A55:
q in A
by A41, TARSKI:def 4;
consider q1 being
set such that A56:
[q1,q] = g . (hh . q)
and
x in q1
and
hh . q in q
and A57:
hh . q in f . x
and A58:
[:q1,q:] c= *graph f
by A51, A55;
hh . q in rng hh
by A50, A55, FUNCT_1:def 5;
then
[q1,q] in g .: (rng hh)
by A14, A56, A57, FUNCT_1:def 12;
then
q1 in B
by RELAT_1:def 4;
then
zz in q1
by A53, SETFAM_1:58;
then
[zz,p] in [:q1,q:]
by A54, ZFMISC_1:106;
hence
p in f . zz
by A58, Th39;
verum
end;
then
aa <= fz
by YELLOW_1:3;
then
a <= f . zz
by A1, YELLOW_0:1;
then
f . zz in P
by A7, A40, WAYBEL_0:def 20;
hence
z in f " P
by FUNCT_2:46;
verum
end; now let c1 be
set ;
( c1 in B implies x in c1 )assume
c1 in B
;
x in c1then consider c being
set such that A59:
[c1,c] in g .: (rng hh)
by RELAT_1:def 4;
consider b being
set such that
b in dom g
and A60:
b in rng hh
and A61:
[c1,c] = g . b
by A59, FUNCT_1:def 12;
consider c9 being
set such that A62:
c9 in dom hh
and A63:
b = hh . c9
by A60, FUNCT_1:def 5;
ex
c91 being
set st
(
[c91,c9] = g . (hh . c9) &
x in c91 &
hh . c9 in c9 &
hh . c9 in f . x &
[:c91,c9:] c= *graph f )
by A50, A51, A62;
hence
x in c1
by A61, A63, ZFMISC_1:33;
verum end; hence
x in Q
by A8, SETFAM_1:58;
verum
end; assume
ex
Q being
Subset of
X st
(
Q is
open &
Q c= f " P &
x in Q )
;
x in f " Phence
x in f " P
;
verum end; hence
f " P is
open
by TOPS_1:57;
verum end;
[#] S <> {}
;
hence
f is continuous
by A6, TOPS_2:55; verum