Let $\mathfrak{q}$ be a 2. Definition 4.9.1 - Primary ideal of $A$. Then $r(\mathfrak{q})$ is 1;; the smallest prime ideal containing $\mathfrak{q}$.

Suppose that $r(\mathfrak{q})=$ 1;;$\mathfrak{p}$. Then we say that $\mathfrak{q}$ is 1;;$\mathfrak{p}$-primary