lf: procedure (n) returns (fixed decimal (31) );
   declare n fixed binary;
   declare (s, f) fixed (31);
   declare (i, j) fixed;

   s = 0;
   do i = n-1 to 0 by -1;
      f = 1;
      do j = i to 1 by -1;
         f = f * j;
      end;
      s = s + f;
   end;
   return (s);
end lf;

   declare n fixed binary;

   do n = 0 to 10, 20 to 30;
      put skip list ('Left factorial of ' || n || '=' || lf(n) );
   end;

end left_factorials;