let r be non negative real number ; for n being non empty Element of NAT
for o being Point of (TOP-REAL n)
for f being continuous Function of (Tdisk (o,r)),(Tdisk (o,r)) st f has_no_fixpoint holds
(BR-map f) | (Sphere (o,r)) = id (Tcircle (o,r))
let n be non empty Element of NAT ; for o being Point of (TOP-REAL n)
for f being continuous Function of (Tdisk (o,r)),(Tdisk (o,r)) st f has_no_fixpoint holds
(BR-map f) | (Sphere (o,r)) = id (Tcircle (o,r))
let o be Point of (TOP-REAL n); for f being continuous Function of (Tdisk (o,r)),(Tdisk (o,r)) st f has_no_fixpoint holds
(BR-map f) | (Sphere (o,r)) = id (Tcircle (o,r))
let f be continuous Function of (Tdisk (o,r)),(Tdisk (o,r)); ( f has_no_fixpoint implies (BR-map f) | (Sphere (o,r)) = id (Tcircle (o,r)) )
assume A1:
f has_no_fixpoint
; (BR-map f) | (Sphere (o,r)) = id (Tcircle (o,r))
set D = cl_Ball (o,r);
set C = Sphere (o,r);
set g = BR-map f;
( dom (BR-map f) = the carrier of (Tdisk (o,r)) & the carrier of (Tdisk (o,r)) = cl_Ball (o,r) )
by Th3, FUNCT_2:def 1;
then A2:
dom ((BR-map f) | (Sphere (o,r))) = Sphere (o,r)
by RELAT_1:62, TOPREAL9:17;
A3:
the carrier of (Tcircle (o,r)) = Sphere (o,r)
by TOPREALB:9;
A4:
for x being set st x in dom ((BR-map f) | (Sphere (o,r))) holds
((BR-map f) | (Sphere (o,r))) . x = (id (Tcircle (o,r))) . x
proof
let x be
set ;
( x in dom ((BR-map f) | (Sphere (o,r))) implies ((BR-map f) | (Sphere (o,r))) . x = (id (Tcircle (o,r))) . x )
assume A5:
x in dom ((BR-map f) | (Sphere (o,r)))
;
((BR-map f) | (Sphere (o,r))) . x = (id (Tcircle (o,r))) . x
reconsider y =
x as
Point of
(Tdisk (o,r)) by A5;
A6:
not
x is_a_fixpoint_of f
by A1, ABIAN:def 5;
thus ((BR-map f) | (Sphere (o,r))) . x =
(BR-map f) . x
by A2, A5, FUNCT_1:49
.=
y
by A2, A3, A5, A6, Th11
.=
(id (Tcircle (o,r))) . x
by A2, A3, A5, FUNCT_1:18
;
verum
end;
dom (id (Tcircle (o,r))) = the carrier of (Tcircle (o,r))
by RELAT_1:45;
hence
(BR-map f) | (Sphere (o,r)) = id (Tcircle (o,r))
by A2, A3, A4, FUNCT_1:2; verum