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_1:91, 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_1:72
.=
y
by A2, A3, A5, A6, Th11
.=
(id (Tcircle o,r)) . x
by A2, A3, A5, FUNCT_1:35
;
verum
end;
dom (id (Tcircle o,r)) = the carrier of (Tcircle o,r)
by RELAT_1:71;
hence
(BR-map f) | (Sphere o,r) = id (Tcircle o,r)
by A2, A3, A4, FUNCT_1:9; verum