hecheng

代码说明：

  设关系A是从集合X={1，2，….，n}到集合Y={1，2，…..，m}的二元关系，而关系B是从集合Y到集合Z={1，2，….，p}的二元关系，求A与B的合成关系C。(A relationship is established from the set X = (1,2, ...., N) to the collection Y = (1,2, ... .., m) of binary relations, the relationship B is from a collection of Y to the set Z = ( 1,2, ...., p) of the binary relation, find the relationship between A and B, synthesis of C.)