let T1, T2 be non empty strict TopSpace; for P being prebasis of T1 st the carrier of T1 = the carrier of T2 & P is prebasis of T2 holds
T1 = T2
let P be prebasis of T1; ( the carrier of T1 = the carrier of T2 & P is prebasis of T2 implies T1 = T2 )
assume that
A1:
the carrier of T1 = the carrier of T2
and
A2:
P is prebasis of T2
; T1 = T2
reconsider P9 = P as prebasis of T2 by A2;
consider B1 being Basis of T1 such that
A3:
B1 c= FinMeetCl P
by Def5;
P c= the topology of T1
by TOPS_2:78;
then
FinMeetCl P c= FinMeetCl the topology of T1
by Th16;
then A4:
UniCl (FinMeetCl P) c= UniCl (FinMeetCl the topology of T1)
by Th9;
P9 c= the topology of T2
by TOPS_2:78;
then
FinMeetCl P9 c= FinMeetCl the topology of T2
by Th16;
then A5:
UniCl (FinMeetCl P9) c= UniCl (FinMeetCl the topology of T2)
by Th9;
A6:
the topology of T1 c= UniCl B1
by Def2;
UniCl B1 c= UniCl (FinMeetCl P)
by A3, Th9;
then A7:
the topology of T1 c= UniCl (FinMeetCl P)
by A6, XBOOLE_1:1;
consider B2 being Basis of T2 such that
A8:
B2 c= FinMeetCl P9
by Def5;
A9:
the topology of T2 c= UniCl B2
by Def2;
UniCl B2 c= UniCl (FinMeetCl P9)
by A8, Th9;
then A10:
the topology of T2 c= UniCl (FinMeetCl P9)
by A9, XBOOLE_1:1;
the topology of T2 = UniCl (FinMeetCl the topology of T2)
by Th7;
then A11:
UniCl (FinMeetCl P9) = the topology of T2
by A10, A5, XBOOLE_0:def 10;
the topology of T1 = UniCl (FinMeetCl the topology of T1)
by Th7;
hence
T1 = T2
by A1, A7, A11, A4, XBOOLE_0:def 10; verum