Let $R$ be a Noetherian ring and $P$ a prime ideal. Then the $n$-th symbolic power of $P$ is $$P^{(n)} = P^n R_P \cap R = \{ f \mid sf \in P^n \text{ for some } s \in R - P\}$$ (cf. wiki). We have $P^{(n)}$ is just the $P$-primary component of $P^n$.
Now, we consider $R = \mathbb{C}[X_1, \ldots, X_d]$ and $V = V(P)$ the variety defined by $P$. For each $a \in V$ we set $\mathfrak{m}_a$ the maximal ideal corresponding with $a$. We have $P = \cap_{a \in V} \mathfrak{m}_a$, since $R$ is a Jacobson ring. $P^{(n)}$ consists of functions with zeros of order $n$ along $V$.
Question 1. With above setting. Are the following equivalent:
- $f \in P^{(n)}$;
- $f \in \mathfrak{m}_a^n$ for all $a \in V$;
- $f, \frac{\partial^{\alpha} f}{\partial X^{\alpha}}$ vanish on $V$ for all $| \alpha | \le n-1$.
It is clear that $(2) \Leftrightarrow (3)$ and we can prove that $(1) \Rightarrow (3)$.
Question 2. Suppose Question has a positive answer. Can we have $(1) \Leftrightarrow (2)$ in more general rings (as Jacobson rings)?