1. 求有限集上给定关系的自反、对称和传递闭包。（有两种求解方法，只做一种为A，两种都做为B）

2. 求有限集上等价关系的数目。（有两种求解方法，只做一种为A，两种都做为B）

-1. Find a limited set of relations on a given reflexive, symmetric and transitive closure. (There are two solution method, only one is A, both are used as B) 2. Seeking a limited number of equivalence relations on the set. (There are two solution method, only one is A, both are used as B)