theorem Th1:
for
N being non
zero Nat for
F being
Element of
N -tuples_on (Funcs ( the carrier of (TOP-REAL (N + 1)), the carrier of R^1)) st ( for
i being
Nat st
i in dom F holds
F . i = PROJ (
(N + 1),
i) ) holds
( ( for
t being
Point of
(TOP-REAL (N + 1)) holds
<:F:> . t = t | N ) & ( for
Sp,
Sn being
Subset of
(TOP-REAL (N + 1)) st
Sp = { u where u is Point of (TOP-REAL (N + 1)) : ( u . (N + 1) >= 0 & |.u.| = 1 ) } &
Sn = { t where t is Point of (TOP-REAL (N + 1)) : ( t . (N + 1) <= 0 & |.t.| = 1 ) } holds
(
<:F:> .: Sp = cl_Ball (
(0. (TOP-REAL N)),1) &
<:F:> .: Sn = cl_Ball (
(0. (TOP-REAL N)),1) &
<:F:> .: (Sp /\ Sn) = Sphere (
(0. (TOP-REAL N)),1) & ( for
H being
Function of
((TOP-REAL (N + 1)) | Sp),
(Tdisk ((0. (TOP-REAL N)),1)) st
H = <:F:> | Sp holds
H is
being_homeomorphism ) & ( for
H being
Function of
((TOP-REAL (N + 1)) | Sn),
(Tdisk ((0. (TOP-REAL N)),1)) st
H = <:F:> | Sn holds
H is
being_homeomorphism ) ) ) )