 Consider the use of the most general categories, yin and yang. Yang labels the tendency to expand and dominate; yin labels the tendency to draw things in by yielding. Anything can be put in one of these two categories, but yin and yang are not inherent properties. The same thing that might be active and dominating in one relationship might be softer and yielding in another (as is commonly the case in Chinese medicine). The function of the labels can be compared to the way we label cause and effect. We can designate a cause and an effect in any change, but being a cause is not an essential property. Everything is simultaneously the cause of many effects and the effect of many causes. As cause and effect illustrate, even a set of binary categories can be helpful in analyzing situations, and yinyang could be specified in various ways. In the Yi Jing, lines representing either yin (a divided line) or yang (a straight line) can be combined into groups of three to form eight trigrams, or groups of six to form 64 categories. Each of these lines could be taken as more or less stable, leading to 4096 possible situations.