use RationalNumbers;

PerfectNumbers( Limit = integer) -> multi(integer);
PerfectNumbers( Limit) =
  	      [ Candidate = 2 .. Limit;
		Sum:= Rational(1,Candidate);
		[ Divisor = 2 .. integer(sqrt(real(Candidate)));
		  if mod(Candidate, Divisor) == 0 then
			Sum := Sum + Rational(1, Divisor) + Rational(Divisor, Candidate);
		];
		if Sum == Rational(1,1) then Candidate
              ];

PerfectNumbers(10000)?