let p, p1, p2 be Point of (TOP-REAL 2); for C being Simple_closed_curve
for A, B, P being Subset of (TOP-REAL 2)
for U being Subset of ((TOP-REAL 2) | (C `))
for r being positive Real st A is_an_arc_of p1,p2 & A c= C & C c= Ball (p,r) & p in U & (Cl P) /\ (P `) c= A & P c= Ball (p,r) holds
for f being Function of (Tdisk (p,r)),((TOP-REAL 2) | A) st f is continuous & f | A = id A & U = P & U is a_component & B = (cl_Ball (p,r)) \ {p} holds
ex g being Function of (Tdisk (p,r)),((TOP-REAL 2) | B) st
( g is continuous & ( for x being Point of (Tdisk (p,r)) holds
( ( x in Cl P implies g . x = f . x ) & ( x in P ` implies g . x = x ) ) ) )
let C be Simple_closed_curve; for A, B, P being Subset of (TOP-REAL 2)
for U being Subset of ((TOP-REAL 2) | (C `))
for r being positive Real st A is_an_arc_of p1,p2 & A c= C & C c= Ball (p,r) & p in U & (Cl P) /\ (P `) c= A & P c= Ball (p,r) holds
for f being Function of (Tdisk (p,r)),((TOP-REAL 2) | A) st f is continuous & f | A = id A & U = P & U is a_component & B = (cl_Ball (p,r)) \ {p} holds
ex g being Function of (Tdisk (p,r)),((TOP-REAL 2) | B) st
( g is continuous & ( for x being Point of (Tdisk (p,r)) holds
( ( x in Cl P implies g . x = f . x ) & ( x in P ` implies g . x = x ) ) ) )
let A, B, P be Subset of (TOP-REAL 2); for U being Subset of ((TOP-REAL 2) | (C `))
for r being positive Real st A is_an_arc_of p1,p2 & A c= C & C c= Ball (p,r) & p in U & (Cl P) /\ (P `) c= A & P c= Ball (p,r) holds
for f being Function of (Tdisk (p,r)),((TOP-REAL 2) | A) st f is continuous & f | A = id A & U = P & U is a_component & B = (cl_Ball (p,r)) \ {p} holds
ex g being Function of (Tdisk (p,r)),((TOP-REAL 2) | B) st
( g is continuous & ( for x being Point of (Tdisk (p,r)) holds
( ( x in Cl P implies g . x = f . x ) & ( x in P ` implies g . x = x ) ) ) )
let U be Subset of ((TOP-REAL 2) | (C `)); for r being positive Real st A is_an_arc_of p1,p2 & A c= C & C c= Ball (p,r) & p in U & (Cl P) /\ (P `) c= A & P c= Ball (p,r) holds
for f being Function of (Tdisk (p,r)),((TOP-REAL 2) | A) st f is continuous & f | A = id A & U = P & U is a_component & B = (cl_Ball (p,r)) \ {p} holds
ex g being Function of (Tdisk (p,r)),((TOP-REAL 2) | B) st
( g is continuous & ( for x being Point of (Tdisk (p,r)) holds
( ( x in Cl P implies g . x = f . x ) & ( x in P ` implies g . x = x ) ) ) )
let r be positive Real; ( A is_an_arc_of p1,p2 & A c= C & C c= Ball (p,r) & p in U & (Cl P) /\ (P `) c= A & P c= Ball (p,r) implies for f being Function of (Tdisk (p,r)),((TOP-REAL 2) | A) st f is continuous & f | A = id A & U = P & U is a_component & B = (cl_Ball (p,r)) \ {p} holds
ex g being Function of (Tdisk (p,r)),((TOP-REAL 2) | B) st
( g is continuous & ( for x being Point of (Tdisk (p,r)) holds
( ( x in Cl P implies g . x = f . x ) & ( x in P ` implies g . x = x ) ) ) ) )
set D = Tdisk (p,r);
assume that
A1:
A is_an_arc_of p1,p2
and
A2:
A c= C
and
A3:
C c= Ball (p,r)
and
A4:
p in U
and
A5:
(Cl P) /\ (P `) c= A
and
A6:
P c= Ball (p,r)
; for f being Function of (Tdisk (p,r)),((TOP-REAL 2) | A) st f is continuous & f | A = id A & U = P & U is a_component & B = (cl_Ball (p,r)) \ {p} holds
ex g being Function of (Tdisk (p,r)),((TOP-REAL 2) | B) st
( g is continuous & ( for x being Point of (Tdisk (p,r)) holds
( ( x in Cl P implies g . x = f . x ) & ( x in P ` implies g . x = x ) ) ) )
let f be Function of (Tdisk (p,r)),((TOP-REAL 2) | A); ( f is continuous & f | A = id A & U = P & U is a_component & B = (cl_Ball (p,r)) \ {p} implies ex g being Function of (Tdisk (p,r)),((TOP-REAL 2) | B) st
( g is continuous & ( for x being Point of (Tdisk (p,r)) holds
( ( x in Cl P implies g . x = f . x ) & ( x in P ` implies g . x = x ) ) ) ) )
assume that
A7:
f is continuous
and
A8:
f | A = id A
and
A9:
U = P
and
A10:
U is a_component
and
A11:
B = (cl_Ball (p,r)) \ {p}
; ex g being Function of (Tdisk (p,r)),((TOP-REAL 2) | B) st
( g is continuous & ( for x being Point of (Tdisk (p,r)) holds
( ( x in Cl P implies g . x = f . x ) & ( x in P ` implies g . x = x ) ) ) )
reconsider B1 = B as non empty Subset of (TOP-REAL 2) by A11;
reconsider T2B1 = (TOP-REAL 2) | B1 as non empty SubSpace of TOP-REAL 2 ;
A12:
the carrier of ((TOP-REAL 2) | (C `)) = C `
by PRE_TOPC:8;
A13:
the carrier of ((TOP-REAL 2) | A) = A
by PRE_TOPC:8;
A14:
the carrier of (Tdisk (p,r)) = cl_Ball (p,r)
by BROUWER:3;
A15:
Ball (p,r) c= cl_Ball (p,r)
by TOPREAL9:16;
A16:
A <> {}
by A1, TOPREAL1:1;
reconsider A1 = A as non empty Subset of (TOP-REAL 2) by A1, TOPREAL1:1;
A17:
not p in C
by A4, A12, XBOOLE_0:def 5;
|.(p - p).| = 0
by TOPRNS_1:28;
then A18:
p in [#] (Tdisk (p,r))
by A14, TOPREAL9:8;
A19:
P c= Cl P
by PRE_TOPC:18;
then reconsider F1 = (Cl P) /\ ([#] (Tdisk (p,r))) as non empty Subset of (Tdisk (p,r)) by A4, A9, A18, XBOOLE_0:def 4;
A20:
Sphere (p,r) c= cl_Ball (p,r)
by TOPREAL9:17;
A21:
Ball (p,r) misses Sphere (p,r)
by TOPREAL9:19;
consider e being Point of (TOP-REAL 2) such that
A22:
e in Sphere (p,r)
by SUBSET_1:4;
not e in P
by A6, A21, A22, XBOOLE_0:3;
then
e in P `
by SUBSET_1:29;
then reconsider F3 = (P `) /\ ([#] (Tdisk (p,r))) as non empty Subset of (Tdisk (p,r)) by A14, A20, A22, XBOOLE_0:def 4;
reconsider T1 = (Tdisk (p,r)) | F1 as non empty SubSpace of Tdisk (p,r) ;
reconsider T3 = (Tdisk (p,r)) | F3 as non empty SubSpace of Tdisk (p,r) ;
A23:
the carrier of T1 = F1
by PRE_TOPC:8;
A24:
the carrier of T3 = F3
by PRE_TOPC:8;
A25:
the carrier of T2B1 = B1
by PRE_TOPC:8;
A26:
A c= B
A28:
F3 c= B
f | F1 is Function of F1,A
by A13, A16, FUNCT_2:32;
then reconsider f1 = f | F1 as Function of T1,T2B1 by A16, A23, A25, A26, FUNCT_2:7;
reconsider g1 = id F3 as Function of T3,T2B1 by A24, A25, A28, FUNCT_2:7;
A30:
F1 = [#] T1
by PRE_TOPC:8;
A31:
F3 = [#] T3
by PRE_TOPC:8;
A32:
([#] T1) \/ ([#] T3) = [#] (Tdisk (p,r))
reconsider DT = [#] (Tdisk (p,r)) as closed Subset of (TOP-REAL 2) by BORSUK_1:def 11, TSEP_1:1;
DT /\ (Cl P) is closed
;
then A34:
F1 is closed
by TSEP_1:8;
P is_a_component_of C `
by A9, A10;
then
P is open
by SPRECT_3:8;
then
DT /\ (P `) is closed
;
then A35:
F3 is closed
by TSEP_1:8;
reconsider f2 = f | F1 as Function of T1,((TOP-REAL 2) | A1) by A23, FUNCT_2:32;
A36:
(TOP-REAL 2) | A1 is SubSpace of T2B1
by A13, A25, A26, TSEP_1:4;
T3 is SubSpace of TOP-REAL 2
by TSEP_1:7;
then A37:
T3 is SubSpace of T2B1
by A24, A25, A28, TSEP_1:4;
f2 is continuous
by A7, TOPMETR:7;
then A38:
f1 is continuous
by A36, PRE_TOPC:26;
reconsider g2 = id F3 as Function of T3,T3 by A24;
g2 = id T3
by PRE_TOPC:8;
then A39:
g1 is continuous
by A37, PRE_TOPC:26;
A40:
for x being set st x in Cl P & x in P ` holds
f . x = x
for x being object st x in ([#] T1) /\ ([#] T3) holds
f1 . x = g1 . x
then consider g being Function of (Tdisk (p,r)),((TOP-REAL 2) | B) such that
A48:
g = f1 +* g1
and
A49:
g is continuous
by A30, A31, A32, A34, A35, A38, A39, JGRAPH_2:1;
take
g
; ( g is continuous & ( for x being Point of (Tdisk (p,r)) holds
( ( x in Cl P implies g . x = f . x ) & ( x in P ` implies g . x = x ) ) ) )
thus
g is continuous
by A49; for x being Point of (Tdisk (p,r)) holds
( ( x in Cl P implies g . x = f . x ) & ( x in P ` implies g . x = x ) )
let x be Point of (Tdisk (p,r)); ( ( x in Cl P implies g . x = f . x ) & ( x in P ` implies g . x = x ) )
A50:
dom g1 = the carrier of T3
by FUNCT_2:def 1;
hereby ( x in P ` implies g . x = x )
end;
assume
x in P `
; g . x = x
then A55:
x in F3
by XBOOLE_0:def 4;
hence g . x =
g1 . x
by A48, A50, FUNCT_4:13
.=
x
by A55, FUNCT_1:18
;
verum