let cn be Real; for K0, B0 being Subset of (TOP-REAL 2)
for f being Function of ((TOP-REAL 2) | K0),((TOP-REAL 2) | B0) st - 1 < cn & cn < 1 & f = (cn -FanMorphS) | K0 & B0 = { q where q is Point of (TOP-REAL 2) : ( q `2 <= 0 & q <> 0. (TOP-REAL 2) ) } & K0 = { p where p is Point of (TOP-REAL 2) : ( (p `1) / |.p.| >= cn & p `2 <= 0 & p <> 0. (TOP-REAL 2) ) } holds
f is continuous
let K0, B0 be Subset of (TOP-REAL 2); for f being Function of ((TOP-REAL 2) | K0),((TOP-REAL 2) | B0) st - 1 < cn & cn < 1 & f = (cn -FanMorphS) | K0 & B0 = { q where q is Point of (TOP-REAL 2) : ( q `2 <= 0 & q <> 0. (TOP-REAL 2) ) } & K0 = { p where p is Point of (TOP-REAL 2) : ( (p `1) / |.p.| >= cn & p `2 <= 0 & p <> 0. (TOP-REAL 2) ) } holds
f is continuous
let f be Function of ((TOP-REAL 2) | K0),((TOP-REAL 2) | B0); ( - 1 < cn & cn < 1 & f = (cn -FanMorphS) | K0 & B0 = { q where q is Point of (TOP-REAL 2) : ( q `2 <= 0 & q <> 0. (TOP-REAL 2) ) } & K0 = { p where p is Point of (TOP-REAL 2) : ( (p `1) / |.p.| >= cn & p `2 <= 0 & p <> 0. (TOP-REAL 2) ) } implies f is continuous )
set sn = - (sqrt (1 - (cn ^2)));
set p0 = |[cn,(- (sqrt (1 - (cn ^2))))]|;
A1:
|[cn,(- (sqrt (1 - (cn ^2))))]| `2 = - (sqrt (1 - (cn ^2)))
by EUCLID:52;
|[cn,(- (sqrt (1 - (cn ^2))))]| `1 = cn
by EUCLID:52;
then A2:
|.|[cn,(- (sqrt (1 - (cn ^2))))]|.| = sqrt (((- (sqrt (1 - (cn ^2)))) ^2) + (cn ^2))
by A1, JGRAPH_3:1;
assume A3:
( - 1 < cn & cn < 1 & f = (cn -FanMorphS) | K0 & B0 = { q where q is Point of (TOP-REAL 2) : ( q `2 <= 0 & q <> 0. (TOP-REAL 2) ) } & K0 = { p where p is Point of (TOP-REAL 2) : ( (p `1) / |.p.| >= cn & p `2 <= 0 & p <> 0. (TOP-REAL 2) ) } )
; f is continuous
then
cn ^2 < 1 ^2
by SQUARE_1:50;
then A4:
1 - (cn ^2) > 0
by XREAL_1:50;
then A5:
- (- (sqrt (1 - (cn ^2)))) > 0
by SQUARE_1:25;
(- (- (sqrt (1 - (cn ^2))))) ^2 = 1 - (cn ^2)
by A4, SQUARE_1:def 2;
then
(|[cn,(- (sqrt (1 - (cn ^2))))]| `1) / |.|[cn,(- (sqrt (1 - (cn ^2))))]|.| = cn
by A2, EUCLID:52;
then A7:
|[cn,(- (sqrt (1 - (cn ^2))))]| in K0
by A3, A1, A6, A5;
then reconsider K1 = K0 as non empty Subset of (TOP-REAL 2) ;
A8:
rng (proj2 * ((cn -FanMorphS) | K1)) c= the carrier of R^1
by TOPMETR:17;
A9:
K0 c= B0
A10:
dom ((cn -FanMorphS) | K1) c= dom (proj1 * ((cn -FanMorphS) | K1))
A13:
rng (proj1 * ((cn -FanMorphS) | K1)) c= the carrier of R^1
by TOPMETR:17;
dom (proj1 * ((cn -FanMorphS) | K1)) c= dom ((cn -FanMorphS) | K1)
by RELAT_1:25;
then dom (proj1 * ((cn -FanMorphS) | K1)) =
dom ((cn -FanMorphS) | K1)
by A10, XBOOLE_0:def 10
.=
(dom (cn -FanMorphS)) /\ K1
by RELAT_1:61
.=
the carrier of (TOP-REAL 2) /\ K1
by FUNCT_2:def 1
.=
K1
by XBOOLE_1:28
.=
the carrier of ((TOP-REAL 2) | K1)
by PRE_TOPC:8
;
then reconsider g2 = proj1 * ((cn -FanMorphS) | K1) as Function of ((TOP-REAL 2) | K1),R^1 by A13, FUNCT_2:2;
for p being Point of (TOP-REAL 2) st p in the carrier of ((TOP-REAL 2) | K1) holds
g2 . p = |.p.| * ((((p `1) / |.p.|) - cn) / (1 - cn))
proof
let p be
Point of
(TOP-REAL 2);
( p in the carrier of ((TOP-REAL 2) | K1) implies g2 . p = |.p.| * ((((p `1) / |.p.|) - cn) / (1 - cn)) )
A14:
dom ((cn -FanMorphS) | K1) =
(dom (cn -FanMorphS)) /\ K1
by RELAT_1:61
.=
the
carrier of
(TOP-REAL 2) /\ K1
by FUNCT_2:def 1
.=
K1
by XBOOLE_1:28
;
A15:
the
carrier of
((TOP-REAL 2) | K1) = K1
by PRE_TOPC:8;
assume A16:
p in the
carrier of
((TOP-REAL 2) | K1)
;
g2 . p = |.p.| * ((((p `1) / |.p.|) - cn) / (1 - cn))
then
ex
p3 being
Point of
(TOP-REAL 2) st
(
p = p3 &
(p3 `1) / |.p3.| >= cn &
p3 `2 <= 0 &
p3 <> 0. (TOP-REAL 2) )
by A3, A15;
then A17:
(cn -FanMorphS) . p = |[(|.p.| * ((((p `1) / |.p.|) - cn) / (1 - cn))),(|.p.| * (- (sqrt (1 - (((((p `1) / |.p.|) - cn) / (1 - cn)) ^2)))))]|
by A3, Th115;
((cn -FanMorphS) | K1) . p = (cn -FanMorphS) . p
by A16, A15, FUNCT_1:49;
then g2 . p =
proj1 . |[(|.p.| * ((((p `1) / |.p.|) - cn) / (1 - cn))),(|.p.| * (- (sqrt (1 - (((((p `1) / |.p.|) - cn) / (1 - cn)) ^2)))))]|
by A16, A14, A15, A17, FUNCT_1:13
.=
|[(|.p.| * ((((p `1) / |.p.|) - cn) / (1 - cn))),(|.p.| * (- (sqrt (1 - (((((p `1) / |.p.|) - cn) / (1 - cn)) ^2)))))]| `1
by PSCOMP_1:def 5
.=
|.p.| * ((((p `1) / |.p.|) - cn) / (1 - cn))
by EUCLID:52
;
hence
g2 . p = |.p.| * ((((p `1) / |.p.|) - cn) / (1 - cn))
;
verum
end;
then consider f2 being Function of ((TOP-REAL 2) | K1),R^1 such that
A18:
for p being Point of (TOP-REAL 2) st p in the carrier of ((TOP-REAL 2) | K1) holds
f2 . p = |.p.| * ((((p `1) / |.p.|) - cn) / (1 - cn))
;
A19:
dom ((cn -FanMorphS) | K1) c= dom (proj2 * ((cn -FanMorphS) | K1))
dom (proj2 * ((cn -FanMorphS) | K1)) c= dom ((cn -FanMorphS) | K1)
by RELAT_1:25;
then dom (proj2 * ((cn -FanMorphS) | K1)) =
dom ((cn -FanMorphS) | K1)
by A19, XBOOLE_0:def 10
.=
(dom (cn -FanMorphS)) /\ K1
by RELAT_1:61
.=
the carrier of (TOP-REAL 2) /\ K1
by FUNCT_2:def 1
.=
K1
by XBOOLE_1:28
.=
the carrier of ((TOP-REAL 2) | K1)
by PRE_TOPC:8
;
then reconsider g1 = proj2 * ((cn -FanMorphS) | K1) as Function of ((TOP-REAL 2) | K1),R^1 by A8, FUNCT_2:2;
for p being Point of (TOP-REAL 2) st p in the carrier of ((TOP-REAL 2) | K1) holds
g1 . p = |.p.| * (- (sqrt (1 - (((((p `1) / |.p.|) - cn) / (1 - cn)) ^2))))
proof
let p be
Point of
(TOP-REAL 2);
( p in the carrier of ((TOP-REAL 2) | K1) implies g1 . p = |.p.| * (- (sqrt (1 - (((((p `1) / |.p.|) - cn) / (1 - cn)) ^2)))) )
A22:
dom ((cn -FanMorphS) | K1) =
(dom (cn -FanMorphS)) /\ K1
by RELAT_1:61
.=
the
carrier of
(TOP-REAL 2) /\ K1
by FUNCT_2:def 1
.=
K1
by XBOOLE_1:28
;
A23:
the
carrier of
((TOP-REAL 2) | K1) = K1
by PRE_TOPC:8;
assume A24:
p in the
carrier of
((TOP-REAL 2) | K1)
;
g1 . p = |.p.| * (- (sqrt (1 - (((((p `1) / |.p.|) - cn) / (1 - cn)) ^2))))
then
ex
p3 being
Point of
(TOP-REAL 2) st
(
p = p3 &
(p3 `1) / |.p3.| >= cn &
p3 `2 <= 0 &
p3 <> 0. (TOP-REAL 2) )
by A3, A23;
then A25:
(cn -FanMorphS) . p = |[(|.p.| * ((((p `1) / |.p.|) - cn) / (1 - cn))),(|.p.| * (- (sqrt (1 - (((((p `1) / |.p.|) - cn) / (1 - cn)) ^2)))))]|
by A3, Th115;
((cn -FanMorphS) | K1) . p = (cn -FanMorphS) . p
by A24, A23, FUNCT_1:49;
then g1 . p =
proj2 . |[(|.p.| * ((((p `1) / |.p.|) - cn) / (1 - cn))),(|.p.| * (- (sqrt (1 - (((((p `1) / |.p.|) - cn) / (1 - cn)) ^2)))))]|
by A24, A22, A23, A25, FUNCT_1:13
.=
|[(|.p.| * ((((p `1) / |.p.|) - cn) / (1 - cn))),(|.p.| * (- (sqrt (1 - (((((p `1) / |.p.|) - cn) / (1 - cn)) ^2)))))]| `2
by PSCOMP_1:def 6
.=
|.p.| * (- (sqrt (1 - (((((p `1) / |.p.|) - cn) / (1 - cn)) ^2))))
by EUCLID:52
;
hence
g1 . p = |.p.| * (- (sqrt (1 - (((((p `1) / |.p.|) - cn) / (1 - cn)) ^2))))
;
verum
end;
then consider f1 being Function of ((TOP-REAL 2) | K1),R^1 such that
A26:
for p being Point of (TOP-REAL 2) st p in the carrier of ((TOP-REAL 2) | K1) holds
f1 . p = |.p.| * (- (sqrt (1 - (((((p `1) / |.p.|) - cn) / (1 - cn)) ^2))))
;
for q being Point of (TOP-REAL 2) st q in the carrier of ((TOP-REAL 2) | K1) holds
( q `2 <= 0 & (q `1) / |.q.| >= cn & q <> 0. (TOP-REAL 2) )
then A28:
f1 is continuous
by A3, A26, Th118;
A29:
for x, y, s, r being Real st |[x,y]| in K1 & s = f2 . |[x,y]| & r = f1 . |[x,y]| holds
f . |[x,y]| = |[s,r]|
proof
let x,
y,
s,
r be
Real;
( |[x,y]| in K1 & s = f2 . |[x,y]| & r = f1 . |[x,y]| implies f . |[x,y]| = |[s,r]| )
assume that A30:
|[x,y]| in K1
and A31:
(
s = f2 . |[x,y]| &
r = f1 . |[x,y]| )
;
f . |[x,y]| = |[s,r]|
set p99 =
|[x,y]|;
A32:
ex
p3 being
Point of
(TOP-REAL 2) st
(
|[x,y]| = p3 &
(p3 `1) / |.p3.| >= cn &
p3 `2 <= 0 &
p3 <> 0. (TOP-REAL 2) )
by A3, A30;
A33:
the
carrier of
((TOP-REAL 2) | K1) = K1
by PRE_TOPC:8;
then A34:
f1 . |[x,y]| = |.|[x,y]|.| * (- (sqrt (1 - (((((|[x,y]| `1) / |.|[x,y]|.|) - cn) / (1 - cn)) ^2))))
by A26, A30;
((cn -FanMorphS) | K0) . |[x,y]| =
(cn -FanMorphS) . |[x,y]|
by A30, FUNCT_1:49
.=
|[(|.|[x,y]|.| * ((((|[x,y]| `1) / |.|[x,y]|.|) - cn) / (1 - cn))),(|.|[x,y]|.| * (- (sqrt (1 - (((((|[x,y]| `1) / |.|[x,y]|.|) - cn) / (1 - cn)) ^2)))))]|
by A3, A32, Th115
.=
|[s,r]|
by A18, A30, A31, A33, A34
;
hence
f . |[x,y]| = |[s,r]|
by A3;
verum
end;
for q being Point of (TOP-REAL 2) st q in the carrier of ((TOP-REAL 2) | K1) holds
( q `2 <= 0 & q <> 0. (TOP-REAL 2) )
then
f2 is continuous
by A3, A18, Th116;
hence
f is continuous
by A7, A9, A28, A29, JGRAPH_2:35; verum