Naive Lie Theory
《Naive Lie Theory》 · 印刷第 132 页 Chapter 8 的群与极大环面约定；第 137 页 Section 8.2 的 Borel 子群约定；第 149 页 Section 8.5 开头的旗簇定义句
$G$ denotes a connected, reductive, linear algebraic group and $T$ is a maximal torus of $G$. […] Let $B$ be a Borel subgroup of $G$ containing $T$. […] The decomposition of 8.3.8 implies a similar result for the homogeneous space $\mathcal B=G/B$, which is called a flag variety (it is uniquely determined by $G$, up to isomorphism).