augmented matrix

《Algebraic and Analytic Geometry》 · 第 161 页 · Section 3.2「Matrix Operations and Elementary Matrices」，定义段

Let $A$ and $B$ be $m\times n$ and $m\times p$ matrices, respectively. By the augmented matrix $(A\mid B)$, we mean the $m\times(n+p)$ matrix $(A\ B)$, that is, the matrix whose first $n$ columns are the columns of $A$, and whose last $p$ columns are the columns of $B$.