let n be Element of NAT ; for r being real number
for x being Point of holds Sphere x,r c= cl_Ball x,r
let r be real number ; for x being Point of holds Sphere x,r c= cl_Ball x,r
let x be Point of ; Sphere x,r c= cl_Ball x,r
reconsider e = x as Point of by TOPREAL3:13;
( Sphere x,r = Sphere e,r & cl_Ball x,r = cl_Ball e,r )
by Th14, Th15;
hence
Sphere x,r c= cl_Ball x,r
by METRIC_1:16; verum