Naive Lie Theory
《Naive Lie Theory》 · 印刷第 21 页 Chapter 2 章首域的约定、第 23 页 2.1.4(4)(b) 对角矩阵群记号、第 43 页 Section 3.2「Diagonalizable groups and tori」，3.2.1 的对象约定与环面定义（省略中间内容）
$k$ is an algebraically closed field and $F$ a subfield. All algebraic varieties are over $k$. […] (b) the group $\mathbf D_n$ of non-singular diagonal matrices; […] Let $G$ be a linear algebraic group. […] $G$ is an algebraic torus (or simply a torus) if it is isomorphic to some $\mathbf D_n$.