theorem
  for S being non empty TopSpace, s being Point of S for x, y being
Element of pi_1(S,s) for P, Q being Loop of s st x = Class(EqRel(S,s),P) & y =
  Class(EqRel(S,s),Q) holds x*y = Class(EqRel(S,s),P+Q) by Lm4;
