let p1, p2, p3, p4 be Point of (TOP-REAL 2); :: thesis: for P being non empty compact Subset of (TOP-REAL 2) st P = { p where p is Point of (TOP-REAL 2) : |.p.| = 1 } & LE p1,p2,P & LE p2,p3,P & LE p3,p4,P & p1 <> p2 & p2 <> p3 & p3 <> p4 holds
ex f being Function of (TOP-REAL 2),(TOP-REAL 2) st
( f is being_homeomorphism & ( for q being Point of (TOP-REAL 2) holds |.(f . q).| = |.q.| ) & |[(- 1),0 ]| = f . p1 & |[0 ,1]| = f . p2 & |[1,0 ]| = f . p3 & |[0 ,(- 1)]| = f . p4 )
let P be non empty compact Subset of (TOP-REAL 2); :: thesis: ( P = { p where p is Point of (TOP-REAL 2) : |.p.| = 1 } & LE p1,p2,P & LE p2,p3,P & LE p3,p4,P & p1 <> p2 & p2 <> p3 & p3 <> p4 implies ex f being Function of (TOP-REAL 2),(TOP-REAL 2) st
( f is being_homeomorphism & ( for q being Point of (TOP-REAL 2) holds |.(f . q).| = |.q.| ) & |[(- 1),0 ]| = f . p1 & |[0 ,1]| = f . p2 & |[1,0 ]| = f . p3 & |[0 ,(- 1)]| = f . p4 ) )
assume A1:
( P = { p where p is Point of (TOP-REAL 2) : |.p.| = 1 } & LE p1,p2,P & LE p2,p3,P & LE p3,p4,P & p1 <> p2 & p2 <> p3 & p3 <> p4 )
; :: thesis: ex f being Function of (TOP-REAL 2),(TOP-REAL 2) st
( f is being_homeomorphism & ( for q being Point of (TOP-REAL 2) holds |.(f . q).| = |.q.| ) & |[(- 1),0 ]| = f . p1 & |[0 ,1]| = f . p2 & |[1,0 ]| = f . p3 & |[0 ,(- 1)]| = f . p4 )
then consider f being Function of (TOP-REAL 2),(TOP-REAL 2), q1, q2, q3, q4 being Point of (TOP-REAL 2) such that
A2:
( f is being_homeomorphism & ( for q being Point of (TOP-REAL 2) holds |.(f . q).| = |.q.| ) & q1 = f . p1 & q2 = f . p2 & q3 = f . p3 & q4 = f . p4 & q1 `1 < 0 & q1 `2 < 0 & q2 `1 < 0 & q2 `2 < 0 & q3 `1 < 0 & q3 `2 < 0 & q4 `1 < 0 & q4 `2 < 0 & LE q1,q2,P & LE q2,q3,P & LE q3,q4,P )
by Th68;
A3:
dom f = the carrier of (TOP-REAL 2)
by FUNCT_2:def 1;
A4:
f is one-to-one
by A2, TOPS_2:def 5;
then A5:
q1 <> q2
by A1, A2, A3, FUNCT_1:def 8;
A6:
q2 <> q3
by A1, A2, A3, A4, FUNCT_1:def 8;
q3 <> q4
by A1, A2, A3, A4, FUNCT_1:def 8;
then consider f2 being Function of (TOP-REAL 2),(TOP-REAL 2) such that
A7:
( f2 is being_homeomorphism & ( for q being Point of (TOP-REAL 2) holds |.(f2 . q).| = |.q.| ) & |[(- 1),0 ]| = f2 . q1 & |[0 ,1]| = f2 . q2 & |[1,0 ]| = f2 . q3 & |[0 ,(- 1)]| = f2 . q4 )
by A1, A2, A5, A6, Th69;
reconsider f3 = f2 * f as Function of (TOP-REAL 2),(TOP-REAL 2) ;
A8:
f3 is being_homeomorphism
by A2, A7, TOPS_2:71;
A9:
dom f3 = the carrier of (TOP-REAL 2)
by FUNCT_2:def 1;
A10:
for q being Point of (TOP-REAL 2) holds |.(f3 . q).| = |.q.|
A11:
f3 . p1 = |[(- 1),0 ]|
by A2, A7, A9, FUNCT_1:22;
A12:
f3 . p2 = |[0 ,1]|
by A2, A7, A9, FUNCT_1:22;
A13:
f3 . p3 = |[1,0 ]|
by A2, A7, A9, FUNCT_1:22;
f3 . p4 = |[0 ,(- 1)]|
by A2, A7, A9, FUNCT_1:22;
hence
ex f being Function of (TOP-REAL 2),(TOP-REAL 2) st
( f is being_homeomorphism & ( for q being Point of (TOP-REAL 2) holds |.(f . q).| = |.q.| ) & |[(- 1),0 ]| = f . p1 & |[0 ,1]| = f . p2 & |[1,0 ]| = f . p3 & |[0 ,(- 1)]| = f . p4 )
by A8, A10, A11, A12, A13; :: thesis: verum