let T be non empty TopSpace; :: thesis: for a, b being Point of T
for P being Path of a,b
for Q being constant Path of b,b st a,b are_connected holds
RePar P,1RP = P + Q
let a, b be Point of T; :: thesis: for P being Path of a,b
for Q being constant Path of b,b st a,b are_connected holds
RePar P,1RP = P + Q
let P be Path of a,b; :: thesis: for Q being constant Path of b,b st a,b are_connected holds
RePar P,1RP = P + Q
let Q be constant Path of b,b; :: thesis: ( a,b are_connected implies RePar P,1RP = P + Q )
set f = RePar P,1RP ;
set g = P + Q;
assume A1:
a,b are_connected
; :: thesis: RePar P,1RP = P + Q
A2:
b,b are_connected
;
for p being Element of I[01] holds (RePar P,1RP ) . p = (P + Q) . p
proof
let p be
Element of
I[01] ;
:: thesis: (RePar P,1RP ) . p = (P + Q) . p
p in the
carrier of
I[01]
;
then A3:
p in dom 1RP
by FUNCT_2:def 1;
0 in the
carrier of
I[01]
by BORSUK_1:86;
then A4:
0 in dom Q
by FUNCT_2:def 1;
A5:
(RePar P,1RP ) . p =
(P * 1RP ) . p
by A1, Def6, Th55
.=
P . (1RP . p)
by A3, FUNCT_1:23
;
per cases
( p <= 1 / 2 or p > 1 / 2 )
;
suppose A7:
p > 1
/ 2
;
:: thesis: (RePar P,1RP ) . p = (P + Q) . pthen
(2 * p) - 1 is
Point of
I[01]
by Th7;
then
(2 * p) - 1
in the
carrier of
I[01]
;
then A8:
(2 * p) - 1
in dom Q
by FUNCT_2:def 1;
(RePar P,1RP ) . p =
P . 1
by A5, A7, Def7
.=
b
by A1, BORSUK_2:def 2
.=
Q . 0
by A2, BORSUK_2:def 2
.=
Q . ((2 * p) - 1)
by A4, A8, FUNCT_1:def 16
.=
(P + Q) . p
by A1, A7, BORSUK_2:def 5
;
hence
(RePar P,1RP ) . p = (P + Q) . p
;
:: thesis: verum end; end;
end;
hence
RePar P,1RP = P + Q
by FUNCT_2:113; :: thesis: verum