let T, S be non empty TopSpace; ( ex h being Function of (T_0-reflex S),(T_0-reflex T) st
( h is being_homeomorphism & T_0-canonical_map T,h * (T_0-canonical_map S) are_fiberwise_equipotent ) implies T,S are_homeomorphic )
set F = T_0-canonical_map T;
set G = T_0-canonical_map S;
set TR = T_0-reflex T;
set SR = T_0-reflex S;
given h being Function of (T_0-reflex S),(T_0-reflex T) such that A1:
h is being_homeomorphism
and
A2:
T_0-canonical_map T,h * (T_0-canonical_map S) are_fiberwise_equipotent
; T,S are_homeomorphic
consider f being Function such that
A3:
dom f = dom (T_0-canonical_map T)
and
A4:
rng f = dom (h * (T_0-canonical_map S))
and
A5:
f is one-to-one
and
A6:
T_0-canonical_map T = (h * (T_0-canonical_map S)) * f
by A2, CLASSES1:77;
A7:
dom f = the carrier of T
by A3, FUNCT_2:def 1;
A8:
h is continuous
by A1;
A9:
h is one-to-one
by A1;
reconsider f = f as Function of T,S by A4, A7, FUNCT_2:def 1, RELSET_1:4;
take
f
; T_0TOPSP:def 1 f is being_homeomorphism
thus A10:
( dom f = [#] T & rng f = [#] S )
by A4, FUNCT_2:def 1; TOPS_2:def 5 ( f is one-to-one & f is continuous & f " is continuous )
A11:
rng h = [#] (T_0-reflex T)
by A1;
A12:
[#] (T_0-reflex S) <> {}
;
A13:
for A being Subset of S st A is open holds
f " A is open
proof
set g =
h * (T_0-canonical_map S);
let A be
Subset of
S;
( A is open implies f " A is open )
set B =
(h * (T_0-canonical_map S)) .: A;
A14:
h " is
continuous
by A1;
assume A15:
A is
open
;
f " A is open
A16:
for
x1,
x2 being
Element of
S st
x1 in A &
(h * (T_0-canonical_map S)) . x1 = (h * (T_0-canonical_map S)) . x2 holds
x2 in A
T_0-canonical_map S is
open
by Th8;
then
(T_0-canonical_map S) .: A is
open
by A15;
then A19:
(h ") " ((T_0-canonical_map S) .: A) is
open
by A12, A14, TOPS_2:43;
A20:
h is
onto
by A11, FUNCT_2:def 3;
h .: ((T_0-canonical_map S) .: A) = (h ") " ((T_0-canonical_map S) .: A)
by A9, FUNCT_1:84;
then
h .: ((T_0-canonical_map S) .: A) is
open
by A9, A19, A20, TOPS_2:def 4;
then A21:
(h * (T_0-canonical_map S)) .: A is
open
by RELAT_1:126;
[#] (T_0-reflex T) <> {}
;
then A22:
(T_0-canonical_map T) " ((h * (T_0-canonical_map S)) .: A) is
open
by A21, TOPS_2:43;
(T_0-canonical_map T) " ((h * (T_0-canonical_map S)) .: A) = f " ((h * (T_0-canonical_map S)) " ((h * (T_0-canonical_map S)) .: A))
by A6, RELAT_1:146;
hence
f " A is
open
by A22, A16, Th1;
verum
end;
A23:
dom h = [#] (T_0-reflex S)
by A1;
A24:
for A being Subset of T st A is open holds
(f ") " A is open
proof
set g =
(h ") * (T_0-canonical_map T);
let A be
Subset of
T;
( A is open implies (f ") " A is open )
set B =
((h ") * (T_0-canonical_map T)) .: A;
assume A25:
A is
open
;
(f ") " A is open
A26:
for
x1,
x2 being
Element of
T st
x1 in A &
((h ") * (T_0-canonical_map T)) . x1 = ((h ") * (T_0-canonical_map T)) . x2 holds
x2 in A
T_0-canonical_map T = h * ((T_0-canonical_map S) * f)
by A6, RELAT_1:36;
then
(h ") * (T_0-canonical_map T) = ((h ") * h) * ((T_0-canonical_map S) * f)
by RELAT_1:36;
then
(h ") * (T_0-canonical_map T) = (id the carrier of (T_0-reflex S)) * ((T_0-canonical_map S) * f)
by A23, A11, A9, TOPS_2:52;
then
((h ") * (T_0-canonical_map T)) * (f ") = ((T_0-canonical_map S) * f) * (f ")
by FUNCT_2:17;
then
((h ") * (T_0-canonical_map T)) * (f ") = (T_0-canonical_map S) * (f * (f "))
by RELAT_1:36;
then
((h ") * (T_0-canonical_map T)) * (f ") = (T_0-canonical_map S) * (id the carrier of S)
by A5, A10, TOPS_2:52;
then
T_0-canonical_map S = ((h ") * (T_0-canonical_map T)) * (f ")
by FUNCT_2:17;
then A30:
(T_0-canonical_map S) " (((h ") * (T_0-canonical_map T)) .: A) = (f ") " (((h ") * (T_0-canonical_map T)) " (((h ") * (T_0-canonical_map T)) .: A))
by RELAT_1:146;
T_0-canonical_map T is
open
by Th8;
then
(T_0-canonical_map T) .: A is
open
by A25;
then A31:
h " ((T_0-canonical_map T) .: A) is
open
by A11, A8, TOPS_2:43;
((h ") * (T_0-canonical_map T)) .: A = (h ") .: ((T_0-canonical_map T) .: A)
by RELAT_1:126;
then
(T_0-canonical_map S) " (((h ") * (T_0-canonical_map T)) .: A) = (T_0-canonical_map S) " (h " ((T_0-canonical_map T) .: A))
by A11, A9, TOPS_2:55;
then
(T_0-canonical_map S) " (((h ") * (T_0-canonical_map T)) .: A) is
open
by A12, A31, TOPS_2:43;
hence
(f ") " A is
open
by A26, A30, Th1;
verum
end;
thus
f is one-to-one
by A5; ( f is continuous & f " is continuous )
[#] S <> {}
;
hence
f is continuous
by A13, TOPS_2:43; f " is continuous
[#] T <> {}
;
hence
f " is continuous
by A24, TOPS_2:43; verum