theorem
  for T being pathwise_connected non empty TopSpace, a, b, c being Point of T
  for f being Path of a,b, g being Path of b,c holds rng f c= rng(f+g)
proof
  let T be pathwise_connected non empty TopSpace;
  let a, b, c be Point of T;
  let f be Path of a,b;
  let g be Path of b,c;
A1: a,b are_connected by BORSUK_2:def 3;
  b,c are_connected by BORSUK_2:def 3;
  hence thesis by A1,Th33;
end;
