There is this sentence from the opening of the fist chapterof 语类 by Zhu Xi:
Baihua version seems to treat the "不是" part as if it ment "是不是" So the sentence would mean something like:
"Does Tai Ji mean that before Heaven and Earth there was a certain mixture of things and is it [i.e. tai ji] a general name for li of Heaven Earth and all things"
But I do not understand why "不是" should have such meaning? Is it a feature of classical Chinese? Why shouldn't it mean:
"Tai Ji is not (不是) a mixture of things that existed before Heaven and Earth, is it [then] a general name for Li of Heaven earth and all things?"
or soemthing like that???