刚刚看电影独立日，里面有一句台词，总统说的："we are fighting for our right to live, to exist, and should we win the day, the fourth of July will no longer be known as an American holiday, but as a ......"
里面and should we win the day这个倒装是什么用法？我觉得是不是应该有个if被省略了？能不能请解释一下这个现象。