let n be Element of NAT ; for r being real number
for x being Point of (TOP-REAL n) holds the carrier of (Tcircle (x,r)) = Sphere (x,r)
let r be real number ; for x being Point of (TOP-REAL n) holds the carrier of (Tcircle (x,r)) = Sphere (x,r)
let x be Point of (TOP-REAL n); the carrier of (Tcircle (x,r)) = Sphere (x,r)
[#] (Tcircle (x,r)) = Sphere (x,r)
by PRE_TOPC:def 5;
hence
the carrier of (Tcircle (x,r)) = Sphere (x,r)
; verum