给出推出范畴Do的中心与积范畴D×D×D的中心是一一对应的,极限范畴Dl的中心与积范畴(D×D×…×D)/I的中心是一一对应的(I是极限范畴Dl中的指标集),函子范畴的子范畴DC'的中心与范畴D的中心可相互确定等结果.
Shows that there is a one-to-one relationship between center of pushout-category D0 and center of product category D×D×D between center of limit-category D1 and center of product category (D×D×…×D)/I. where I is an index set in limit-category D1. Moreover, center of subcategory of functor category and the one of category D are determined by each other.