let X, Y be non empty TopSpace; for x being Point of X
for f being Function of [:Y,(X | {x}):],Y st f = pr1 ( the carrier of Y,{x}) holds
f " = <:(id Y),(Y --> x):>
let x be Point of X; for f being Function of [:Y,(X | {x}):],Y st f = pr1 ( the carrier of Y,{x}) holds
f " = <:(id Y),(Y --> x):>
let f be Function of [:Y,(X | {x}):],Y; ( f = pr1 ( the carrier of Y,{x}) implies f " = <:(id Y),(Y --> x):> )
set Z = {x};
set idZ = id Y;
A1:
rng (id Y) c= the carrier of Y
;
assume A2:
f = pr1 ( the carrier of Y,{x})
; f " = <:(id Y),(Y --> x):>
then A3:
rng f = the carrier of Y
by FUNCT_3:44;
reconsider Z = {x} as non empty Subset of X ;
reconsider idY = Y --> x as continuous Function of Y,(X | Z) by Th2;
reconsider KA = <:(id Y),idY:> as continuous Function of Y,[:Y,(X | Z):] by YELLOW12:41;
A4:
[: the carrier of Y,Z:] c= rng KA
proof
let y be
object ;
TARSKI:def 3 ( not y in [: the carrier of Y,Z:] or y in rng KA )
assume
y in [: the carrier of Y,Z:]
;
y in rng KA
then consider y1,
y2 being
object such that A5:
y1 in the
carrier of
Y
and A6:
(
y2 in {x} &
y = [y1,y2] )
by ZFMISC_1:def 2;
A7:
y = [y1,x]
by A6, TARSKI:def 1;
A8:
idY . y1 =
( the carrier of Y --> x) . y1
.=
x
by A5, FUNCOP_1:7
;
A9:
y1 in dom KA
by A5, FUNCT_2:def 1;
then KA . y1 =
[((id Y) . y1),(idY . y1)]
by FUNCT_3:def 7
.=
[y1,x]
by A5, A8, FUNCT_1:18
;
hence
y in rng KA
by A7, A9, FUNCT_1:def 3;
verum
end;
rng idY c= the carrier of (X | Z)
;
then A10:
rng idY c= Z
by PRE_TOPC:8;
then
( rng KA c= [:(rng (id Y)),(rng idY):] & [:(rng (id Y)),(rng idY):] c= [: the carrier of Y,Z:] )
by FUNCT_3:51, ZFMISC_1:96;
then
rng KA c= [: the carrier of Y,Z:]
;
then A11: rng KA =
[: the carrier of Y,Z:]
by A4
.=
dom f
by A2, FUNCT_3:def 4
;
A12:
f is one-to-one
by A2, Th4;
A13:
f is onto
by A3, FUNCT_2:def 3;
dom idY =
the carrier of Y
by FUNCT_2:def 1
.=
dom (id Y)
by FUNCT_2:def 1
;
then
f * KA = id (rng f)
by A2, A3, A10, A1, FUNCT_3:52;
then
KA = f "
by A12, A11, FUNCT_1:42;
hence
f " = <:(id Y),(Y --> x):>
by A12, A13, TOPS_2:def 4; verum