MODULE FactorialTest;

CONST Size = 3;

VAR limit := Factorial(Size);

PROC f := Factorial(n) IS 
  IF 
    n <= 1 -> f := 1 
  | f := n * Factorial(n - 1) 
  FI 
END;

PROC P(a, b) IS 
  VAR 
    i = 0, n = limit, 
    c = (1 / n, 0) REL (a, b) 
  IN 
    DO 
      i <= n -> 
        PS.MoveTo((i, 0) REL (a, c)); 
        PS.LineTo((i, LN(Factorial(i))) REL 
                  (a, c)); 
        PS.Stroke(); 
        i := i + 1 
    OD 
  END 
END;