reserve i,j,k,n,m for Nat;

theorem Th7:
  for A being non empty Subset of TOP-REAL 2, p being Element of
  Euclid 2, r being Real st A = Ball(p,r) holds A is connected
proof
  let A be non empty Subset of TOP-REAL 2, p be Element of Euclid 2, r be Real
  such that
A1: A = Ball(p,r);
  A is convex
  by A1,TOPREAL3:21;
  hence thesis;
end;
