theorem Th16:
for
n being
Nat for
p being
Point of
(TOP-REAL n) for
r,
s being
Real st
s > 0 holds
(
(mlt (s,(TOP-REAL n))) .: (Ball (p,r)) = Ball (
(s * p),
(r * s)) &
(mlt (s,(TOP-REAL n))) .: (cl_Ball (p,r)) = cl_Ball (
(s * p),
(r * s)) &
(mlt (s,(TOP-REAL n))) .: (Sphere (p,r)) = Sphere (
(s * p),
(r * s)) )