const func integer: intPow (in var integer: base, in var integer: exponent) is func
  result
    var integer: result is 0;
  begin
    if exponent < 0 then
      raise(NUMERIC_ERROR);
    else
      if odd(exponent) then
        result := base;
      else
        result := 1;
      end if;
      exponent := exponent div 2;
      while exponent <> 0 do
        base *:= base;
        if odd(exponent) then
          result *:= base;
        end if;
        exponent := exponent div 2;
      end while;
    end if;
  end func;