
theorem
  for A1,A2 being set, b1 being Rbag of A1, b2 being Rbag of A2 st b1 =
  b2 holds Sum b1 = Sum b2
proof
  let A1,A2 be set, b1 be Rbag of A1, b2 be Rbag of A2;
  assume b1 = b2;
  then ex f1 being FinSequence of REAL st Sum b1 = Sum f1 & f1 = b2*canFS(
  support b2) by UPROOTS:def 3;
  hence thesis by UPROOTS:def 3;
end;
