答案1
如果您需要的不仅仅是普通的 TeX,您可以输入eplain
,因此也添加对颜色的支持。
\input eplain
\beginpackages
\usepackage{color}
\endpackages
\definecolor{myred}{RGB}{191,19,18}
$$
\left[\matrix{
\textcolor{myred}{A_{11}} & A_{12} & A_{13} & \dots & A_{1n} \cr
A_{21} & \textcolor{myred}{A_{22}} & A_{23} & \dots & A_{2n} \cr
A_{31} & A_{32} & \textcolor{myred}{A_{33}} & \dots & A_{3n} \cr
A_{41} & A_{42} & A_{43} & \dots & A_{4n} \cr
\vdots & \vdots & \vdots & \ddots & \vdots \cr
A_{n1} & A_{n2} & A_{n3} & \dots & \textcolor{myred}{A_{nn}} \cr
}\right]
$$
\bye
相同之处opmac
:
\input opmac
\def\myred{\localcolor\setcmykcolor{0 0.9 0.9 0.25}}
$$
\left[\matrix{
\myred A_{11} & A_{12} & A_{13} & \dots & A_{1n} \cr
A_{21} & \myred A_{22} & A_{23} & \dots & A_{2n} \cr
A_{31} & A_{32} & \myred A_{33} & \dots & A_{3n} \cr
A_{41} & A_{42} & A_{43} & \dots & A_{4n} \cr
\vdots & \vdots & \vdots & \ddots & \vdots \cr
A_{n1} & A_{n2} & A_{n3} & \dots & \myred A_{nn} \cr
}\right]
$$
\bye