《陈书·列传·卷二十四》
处于后面而望前面，那么是前面；处于前面而望后面，那么就是后面。
夫居后而望前，则为前；居前而望后，则为后。
Standing in the back and looking at the front, then it is the front; standing in the front and looking at the back, then it is the back.