 reserve n,m for Nat,
         p,q for Point of TOP-REAL n, r for Real;

theorem :: MFOLD_1:4
  the carrier of Tball(p,r) = Ball(p,r)
proof
  [#]Tball(p,r) = Ball(p,r) by PRE_TOPC:def 5;
  hence thesis;
end;
