let sn 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 < sn & sn < 1 & f = (sn -FanMorphE ) | K0 & B0 = { q where q is Point of (TOP-REAL 2) : ( q `1 >= 0 & q <> 0. (TOP-REAL 2) ) } & K0 = { p where p is Point of (TOP-REAL 2) : ( (p `2 ) / |.p.| <= sn & p `1 >= 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 < sn & sn < 1 & f = (sn -FanMorphE ) | K0 & B0 = { q where q is Point of (TOP-REAL 2) : ( q `1 >= 0 & q <> 0. (TOP-REAL 2) ) } & K0 = { p where p is Point of (TOP-REAL 2) : ( (p `2 ) / |.p.| <= sn & p `1 >= 0 & p <> 0. (TOP-REAL 2) ) } holds
f is continuous
let f be Function of ((TOP-REAL 2) | K0),((TOP-REAL 2) | B0); ( - 1 < sn & sn < 1 & f = (sn -FanMorphE ) | K0 & B0 = { q where q is Point of (TOP-REAL 2) : ( q `1 >= 0 & q <> 0. (TOP-REAL 2) ) } & K0 = { p where p is Point of (TOP-REAL 2) : ( (p `2 ) / |.p.| <= sn & p `1 >= 0 & p <> 0. (TOP-REAL 2) ) } implies f is continuous )
set cn = sqrt (1 - (sn ^2 ));
set p0 = |[(sqrt (1 - (sn ^2 ))),sn]|;
A1:
|[(sqrt (1 - (sn ^2 ))),sn]| `1 = sqrt (1 - (sn ^2 ))
by EUCLID:56;
|[(sqrt (1 - (sn ^2 ))),sn]| `2 = sn
by EUCLID:56;
then A2:
|.|[(sqrt (1 - (sn ^2 ))),sn]|.| = sqrt (((sqrt (1 - (sn ^2 ))) ^2 ) + (sn ^2 ))
by A1, JGRAPH_3:10;
assume A3:
( - 1 < sn & sn < 1 & f = (sn -FanMorphE ) | K0 & B0 = { q where q is Point of (TOP-REAL 2) : ( q `1 >= 0 & q <> 0. (TOP-REAL 2) ) } & K0 = { p where p is Point of (TOP-REAL 2) : ( (p `2 ) / |.p.| <= sn & p `1 >= 0 & p <> 0. (TOP-REAL 2) ) } )
; f is continuous
then
sn ^2 < 1 ^2
by SQUARE_1:120;
then A4:
1 - (sn ^2 ) > 0
by XREAL_1:52;
then A5:
- (- (sqrt (1 - (sn ^2 )))) > 0
by SQUARE_1:93;
(sqrt (1 - (sn ^2 ))) ^2 = 1 - (sn ^2 )
by A4, SQUARE_1:def 4;
then
(|[(sqrt (1 - (sn ^2 ))),sn]| `2 ) / |.|[(sqrt (1 - (sn ^2 ))),sn]|.| = sn
by A2, EUCLID:56, SQUARE_1:83;
then A6:
|[(sqrt (1 - (sn ^2 ))),sn]| in K0
by A3, A1, A5, JGRAPH_2:11;
then reconsider K1 = K0 as non empty Subset of (TOP-REAL 2) ;
A7:
rng (proj1 * ((sn -FanMorphE ) | K1)) c= the carrier of R^1
by TOPMETR:24;
A8:
K0 c= B0
A9:
dom ((sn -FanMorphE ) | K1) c= dom (proj2 * ((sn -FanMorphE ) | K1))
A12:
rng (proj2 * ((sn -FanMorphE ) | K1)) c= the carrier of R^1
by TOPMETR:24;
dom (proj2 * ((sn -FanMorphE ) | K1)) c= dom ((sn -FanMorphE ) | K1)
by RELAT_1:44;
then dom (proj2 * ((sn -FanMorphE ) | K1)) =
dom ((sn -FanMorphE ) | K1)
by A9, XBOOLE_0:def 10
.=
(dom (sn -FanMorphE )) /\ K1
by RELAT_1:90
.=
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:29
;
then reconsider g2 = proj2 * ((sn -FanMorphE ) | K1) as Function of ((TOP-REAL 2) | K1),R^1 by A12, FUNCT_2:4;
for p being Point of (TOP-REAL 2) st p in the carrier of ((TOP-REAL 2) | K1) holds
g2 . p = |.p.| * ((((p `2 ) / |.p.|) - sn) / (1 + sn))
proof
let p be
Point of
(TOP-REAL 2);
( p in the carrier of ((TOP-REAL 2) | K1) implies g2 . p = |.p.| * ((((p `2 ) / |.p.|) - sn) / (1 + sn)) )
A13:
dom ((sn -FanMorphE ) | K1) =
(dom (sn -FanMorphE )) /\ K1
by RELAT_1:90
.=
the
carrier of
(TOP-REAL 2) /\ K1
by FUNCT_2:def 1
.=
K1
by XBOOLE_1:28
;
A14:
the
carrier of
((TOP-REAL 2) | K1) = K1
by PRE_TOPC:29;
assume A15:
p in the
carrier of
((TOP-REAL 2) | K1)
;
g2 . p = |.p.| * ((((p `2 ) / |.p.|) - sn) / (1 + sn))
then
ex
p3 being
Point of
(TOP-REAL 2) st
(
p = p3 &
(p3 `2 ) / |.p3.| <= sn &
p3 `1 >= 0 &
p3 <> 0. (TOP-REAL 2) )
by A3, A14;
then A16:
(sn -FanMorphE ) . p = |[(|.p.| * (sqrt (1 - (((((p `2 ) / |.p.|) - sn) / (1 + sn)) ^2 )))),(|.p.| * ((((p `2 ) / |.p.|) - sn) / (1 + sn)))]|
by A3, Th91;
((sn -FanMorphE ) | K1) . p = (sn -FanMorphE ) . p
by A15, A14, FUNCT_1:72;
then g2 . p =
proj2 . |[(|.p.| * (sqrt (1 - (((((p `2 ) / |.p.|) - sn) / (1 + sn)) ^2 )))),(|.p.| * ((((p `2 ) / |.p.|) - sn) / (1 + sn)))]|
by A15, A13, A14, A16, FUNCT_1:23
.=
|[(|.p.| * (sqrt (1 - (((((p `2 ) / |.p.|) - sn) / (1 + sn)) ^2 )))),(|.p.| * ((((p `2 ) / |.p.|) - sn) / (1 + sn)))]| `2
by PSCOMP_1:def 29
.=
|.p.| * ((((p `2 ) / |.p.|) - sn) / (1 + sn))
by EUCLID:56
;
hence
g2 . p = |.p.| * ((((p `2 ) / |.p.|) - sn) / (1 + sn))
;
verum
end;
then consider f2 being Function of ((TOP-REAL 2) | K1),R^1 such that
A17:
for p being Point of (TOP-REAL 2) st p in the carrier of ((TOP-REAL 2) | K1) holds
f2 . p = |.p.| * ((((p `2 ) / |.p.|) - sn) / (1 + sn))
;
A18:
dom ((sn -FanMorphE ) | K1) c= dom (proj1 * ((sn -FanMorphE ) | K1))
dom (proj1 * ((sn -FanMorphE ) | K1)) c= dom ((sn -FanMorphE ) | K1)
by RELAT_1:44;
then dom (proj1 * ((sn -FanMorphE ) | K1)) =
dom ((sn -FanMorphE ) | K1)
by A18, XBOOLE_0:def 10
.=
(dom (sn -FanMorphE )) /\ K1
by RELAT_1:90
.=
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:29
;
then reconsider g1 = proj1 * ((sn -FanMorphE ) | K1) as Function of ((TOP-REAL 2) | K1),R^1 by A7, FUNCT_2:4;
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 `2 ) / |.p.|) - sn) / (1 + sn)) ^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 `2 ) / |.p.|) - sn) / (1 + sn)) ^2 ))) )
A21:
dom ((sn -FanMorphE ) | K1) =
(dom (sn -FanMorphE )) /\ K1
by RELAT_1:90
.=
the
carrier of
(TOP-REAL 2) /\ K1
by FUNCT_2:def 1
.=
K1
by XBOOLE_1:28
;
A22:
the
carrier of
((TOP-REAL 2) | K1) = K1
by PRE_TOPC:29;
assume A23:
p in the
carrier of
((TOP-REAL 2) | K1)
;
g1 . p = |.p.| * (sqrt (1 - (((((p `2 ) / |.p.|) - sn) / (1 + sn)) ^2 )))
then
ex
p3 being
Point of
(TOP-REAL 2) st
(
p = p3 &
(p3 `2 ) / |.p3.| <= sn &
p3 `1 >= 0 &
p3 <> 0. (TOP-REAL 2) )
by A3, A22;
then A24:
(sn -FanMorphE ) . p = |[(|.p.| * (sqrt (1 - (((((p `2 ) / |.p.|) - sn) / (1 + sn)) ^2 )))),(|.p.| * ((((p `2 ) / |.p.|) - sn) / (1 + sn)))]|
by A3, Th91;
((sn -FanMorphE ) | K1) . p = (sn -FanMorphE ) . p
by A23, A22, FUNCT_1:72;
then g1 . p =
proj1 . |[(|.p.| * (sqrt (1 - (((((p `2 ) / |.p.|) - sn) / (1 + sn)) ^2 )))),(|.p.| * ((((p `2 ) / |.p.|) - sn) / (1 + sn)))]|
by A23, A21, A22, A24, FUNCT_1:23
.=
|[(|.p.| * (sqrt (1 - (((((p `2 ) / |.p.|) - sn) / (1 + sn)) ^2 )))),(|.p.| * ((((p `2 ) / |.p.|) - sn) / (1 + sn)))]| `1
by PSCOMP_1:def 28
.=
|.p.| * (sqrt (1 - (((((p `2 ) / |.p.|) - sn) / (1 + sn)) ^2 )))
by EUCLID:56
;
hence
g1 . p = |.p.| * (sqrt (1 - (((((p `2 ) / |.p.|) - sn) / (1 + sn)) ^2 )))
;
verum
end;
then consider f1 being Function of ((TOP-REAL 2) | K1),R^1 such that
A25:
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 `2 ) / |.p.|) - sn) / (1 + sn)) ^2 )))
;
for q being Point of (TOP-REAL 2) st q in the carrier of ((TOP-REAL 2) | K1) holds
( q `1 >= 0 & (q `2 ) / |.q.| <= sn & q <> 0. (TOP-REAL 2) )
then A27:
f1 is continuous
by A3, A25, Th95;
A28:
for x, y, r, s being real number st |[x,y]| in K1 & r = f1 . |[x,y]| & s = f2 . |[x,y]| holds
f . |[x,y]| = |[r,s]|
proof
let x,
y,
r,
s be
real number ;
( |[x,y]| in K1 & r = f1 . |[x,y]| & s = f2 . |[x,y]| implies f . |[x,y]| = |[r,s]| )
assume that A29:
|[x,y]| in K1
and A30:
(
r = f1 . |[x,y]| &
s = f2 . |[x,y]| )
;
f . |[x,y]| = |[r,s]|
set p99 =
|[x,y]|;
A31:
ex
p3 being
Point of
(TOP-REAL 2) st
(
|[x,y]| = p3 &
(p3 `2 ) / |.p3.| <= sn &
p3 `1 >= 0 &
p3 <> 0. (TOP-REAL 2) )
by A3, A29;
A32:
the
carrier of
((TOP-REAL 2) | K1) = K1
by PRE_TOPC:29;
then A33:
f1 . |[x,y]| = |.|[x,y]|.| * (sqrt (1 - (((((|[x,y]| `2 ) / |.|[x,y]|.|) - sn) / (1 + sn)) ^2 )))
by A25, A29;
((sn -FanMorphE ) | K0) . |[x,y]| =
(sn -FanMorphE ) . |[x,y]|
by A29, FUNCT_1:72
.=
|[(|.|[x,y]|.| * (sqrt (1 - (((((|[x,y]| `2 ) / |.|[x,y]|.|) - sn) / (1 + sn)) ^2 )))),(|.|[x,y]|.| * ((((|[x,y]| `2 ) / |.|[x,y]|.|) - sn) / (1 + sn)))]|
by A3, A31, Th91
.=
|[r,s]|
by A17, A29, A30, A32, A33
;
hence
f . |[x,y]| = |[r,s]|
by A3;
verum
end;
for q being Point of (TOP-REAL 2) st q in the carrier of ((TOP-REAL 2) | K1) holds
( q `1 >= 0 & q <> 0. (TOP-REAL 2) )
then
f2 is continuous
by A3, A17, Th93;
hence
f is continuous
by A6, A8, A27, A28, JGRAPH_2:45; verum