习题 8, § 1

设A为诺特环，a是$x \in M$的A、M有限生成A-模和M由……组成的P子模的理想，使得$ax = 0$。 Show that $\operatorname{Ass}(M/P) \subset \operatorname{Ass}(M)$ (note that for all $x \in M$ the annihilator of $(Ax + P)/P$ is also that of $ax$ and use Exercise 7 (a)).