Let $R := k[x_1, \cdots, x_n, \cdots]/(x_1^1, \cdots , x^n_n, \cdots),$ where $k$ is a field. Set $I:=(x_1, \cdots, x_n, \cdots)$. the questions are: > Is $\inf\{i\in \mathbb N \cup \{0\}\cup\infty\mid Ext^i_R(R/I,M)\neq 0\}=0?$ In the case of $S := k[x_1, \cdots, x_n]/(x_1^1, \cdots , x^n_n),$ and $J:=(x_1, \cdots, x_n)$, there is, (If I'm not mistaken), an affirmative answer because of *Rees*' theorem (B-H,1.2.5). But I've not any idea about the questions above. What about: $\inf\{i\in \mathbb N \cup \{0\}\cup\infty\mid \lim_{\to_n} Ext^i_R(R/I^n,M)\neq 0\}=0?$ thank you.