resource factorial()
   procedure fact(k: int) returns f: int
      if k < 0 -> f := -1
      [] k = 0 or k = 1 -> f := 1
      [] k > 1 -> f := k * fact(k-1)
      fi
   end fact

   var n: int
   writes("How many factorials? "); read(n)
   write()   # generate a linefeed, resulting in a blank line
   fa i := 1 to n ->
      write(i, "factorial is", fact(i))
   af
end factorial

/* ............... Example compile and run(s)

% sr -o factorial factorial.sr
% ./factorial
How many factorials? 5

1 factorial is 1
2 factorial is 2
3 factorial is 6
4 factorial is 24
5 factorial is 120
                                              */