theorem Th55:
for
n being non
zero Nat for
p,
x,
y,
x1,
y1 being
Point of
(TOP-REAL n) for
r being
positive Real st
x,
y are_antipodals_of 0. (TOP-REAL n),1 &
x1 = (CircleIso (p,r)) . x &
y1 = (CircleIso (p,r)) . y holds
x1,
y1 are_antipodals_of p,
r