RosettaCodeData/Task/Perfect-numbers/PL-I/perfect-numbers.pli

perfect: procedure (n) returns (bit(1));
   declare n fixed;
   declare sum fixed;
   declare i fixed binary;

   sum = 0;
   do i = 1 to n-1;
      if mod(n, i) = 0 then sum = sum + i;
   end;
   return (sum=n);
end perfect;