数据库关系代数交运算谢谢了,

数据库关系代数交运算谢谢了,
关系R、S分别为图所示,求 RS _______________ _______________ R A B C S A B C ------------------------- ------------------------ a1 b1 c1 a1 b2 c2 a1 b2 c2 a1 b3 c2 a2 b2 c1 a2 b2 c1 _________________________ ______________________ R∩S A B C ------------------------- a1 b2 c2 a2 b2 c1 ______________ 的解法对么?