Abstract Algebra
《Abstract Algebra》 · 第 750 页 · Chapter 16 首段约定及 Section 16.1「Artinian Rings」，Definition
Throughout this chapter $R$ will denote a commutative ring with $1\neq0$. […] The Jacobson radical of $R$ is the intersection of all maximal ideals of $R$ and is denoted by $\operatorname{Jac}R$.