const func array integer: factorise (in var integer: number) is func
  result
    var array integer: result is 0 times 0;
  local
    var integer: checker is 2;
  begin
    while checker * checker <= number do
      if number rem checker = 0 then
        result &:= [](checker);
        number := number div checker;
      else
        incr(checker);
      end if;
    end while;
    if number <> 1 then
      result &:= [](number);
    end if;
  end func;