let T, S be non empty TopSpace; :: thesis: ( 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
; :: thesis: T,S are_homeomorphic
consider f being Function such that
A3:
( dom f = dom (T_0-canonical_map T) & rng f = dom (h * (T_0-canonical_map S)) & f is one-to-one & T_0-canonical_map T = (h * (T_0-canonical_map S)) * f )
by A2, CLASSES1:85;
( dom f = the carrier of T & rng f = the carrier of S )
by A3, FUNCT_2:def 1;
then reconsider f = f as Function of T,S by FUNCT_2:def 1, RELSET_1:11;
take
f
; :: according to T_0TOPSP:def 1 :: thesis: f is being_homeomorphism
A4:
( [#] (T_0-reflex S) <> {} & [#] S <> {} & [#] T <> {} )
;
thus A5:
( dom f = [#] T & rng f = [#] S )
by A3, FUNCT_2:def 1; :: according to TOPS_2:def 5 :: thesis: ( f is one-to-one & f is continuous & f " is continuous )
thus
f is one-to-one
by A3; :: thesis: ( f is continuous & f " is continuous )
A6:
( dom h = [#] (T_0-reflex S) & rng h = [#] (T_0-reflex T) & h is one-to-one & h is continuous & h " is continuous )
by A1, TOPS_2:def 5;
for A being Subset of S st A is open holds
f " A is open
proof
let A be
Subset of
S;
:: thesis: ( A is open implies f " A is open )
assume A7:
A is
open
;
:: thesis: f " A is open
T_0-canonical_map S is
open
by Th12;
then A8:
(T_0-canonical_map S) .: A is
open
by A7, Def2;
h " is
continuous
by A1, TOPS_2:def 5;
then A9:
(h " ) " ((T_0-canonical_map S) .: A) is
open
by A4, A8, TOPS_2:55;
h .: ((T_0-canonical_map S) .: A) = (h " ) " ((T_0-canonical_map S) .: A)
by A6, FUNCT_1:154;
then
h .: ((T_0-canonical_map S) .: A) is
open
by A6, A9, TOPS_2:def 4;
then A10:
(h * (T_0-canonical_map S)) .: A is
open
by RELAT_1:159;
set g =
h * (T_0-canonical_map S);
set B =
(h * (T_0-canonical_map S)) .: A;
[#] (T_0-reflex T) <> {}
;
then A11:
(T_0-canonical_map T) " ((h * (T_0-canonical_map S)) .: A) is
open
by A10, TOPS_2:55;
A12:
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 T) " ((h * (T_0-canonical_map S)) .: A) = f " ((h * (T_0-canonical_map S)) " ((h * (T_0-canonical_map S)) .: A))
by A3, RELAT_1:181;
hence
f " A is
open
by A11, A12, Th2;
:: thesis: verum
end;
hence
f is continuous
by A4, TOPS_2:55; :: thesis: f " is continuous
for A being Subset of T st A is open holds
(f " ) " A is open
hence
f " is continuous
by A4, TOPS_2:55; :: thesis: verum