 Xuanxue was important for establishing the metaphysical vocabulary used in later Chinese philosophy. One of the most important terms is li 理, which in its original use was a verb for laying out borders according to the contours of the land, or for carving jade according to its own patterns. Both Wang Bi and Guo Xiang use li as a technical term—for Wang Bi li refers to the patterns of coherence represented by the hexagrams of the Yi Jing, while for Guo Xiang li refers to patterns of differentiation that spontaneously arise in the world (Ziporyn 2014: 137–84). Li was later used by Chinese Buddhists to refer to emptiness and by Neo-Confucians to refer to patterns of coherence. The latter is discussed in Section 7.