有人建议我把这个问题作为一个新问题发布。不久前，这个绝妙的解决方案被发布在这个网站上。
\documentclass{article}
\usepackage{tikz,xparse}
\ExplSyntaxOn
\NewDocumentCommand{\calcinput}{m}
{
\tl_map_inline:nn { #1 } { ##1 \hspace{0pt} }
}
\ExplSyntaxOff
\begin{document}
\def\quest{\calcinput{1/(4.2+5.4)-(3.5+4.7)/9}}
\def\ans{\calcinput{-0.806944444}}
\begin{tikzpicture}[font=\Large\ttfamily]
\draw (0,0) rectangle (5,-4);
\node[align=flush left,text width =5cm,
anchor=north west,inner sep=1pt] (qu) {\quest};
\node[align=right,text width =5cm,
anchor=north west,inner sep=1pt] (an) at (qu.south west) {\ans};
\end{tikzpicture}
\begin{tikzpicture}[font=\Large\ttfamily]
\draw (0,0) rectangle (4,-4);
\node[align=flush left,text width =4cm,
anchor=north west,inner sep=1pt] (qu) {\quest};
\node[align=right,text width =4cm,
anchor=north west,inner sep=1pt] (an) at (qu.south west) {\ans};
\end{tikzpicture}
\end{document}
然而，在我为学生编写的一些练习题上模拟计算器时，我需要模拟平方根符号。当我尝试这样做时：
\def\quest{\calcinput{normalcdf(.53,1E99,.5,$\sqrt{\phantom{i}}$(.5*.5/100))}}
我收到此错误：
./Untitled.tex:20: Missing { inserted.
<to be read again>
\let
l.20 ...hor=north west,inner sep=1pt] (qu) {\quest
};
有什么解决方法的建议吗？
答案1
定义
\newcommand{\tsurd}{\ensuremath{\surd}}
和
\documentclass{article}
\usepackage{tikz,xparse}
\newcommand\tsurd{\ensuremath{\surd}}
\ExplSyntaxOn
\NewDocumentCommand{\calcinput}{m}
{
\tl_map_inline:nn { #1 } { ##1 \hspace{0pt} }
}
\ExplSyntaxOff
\begin{document}
\def\quest{\calcinput{normalcdf(.53,1E99,.5,\tsurd(.5*.5/100))}}
\def\ans{\calcinput{-0.806944444}}
\begin{tikzpicture}[font=\Large\ttfamily]
\draw (0,0) rectangle (5,-4);
\node[align=flush left,text width =5cm,
anchor=north west,inner sep=1pt] (qu) {\quest};
\node[align=right,text width =5cm,
anchor=north west,inner sep=1pt] (an) at (qu.south west) {\ans};
\end{tikzpicture}
\begin{tikzpicture}[font=\Large\ttfamily]
\draw (0,0) rectangle (4,-4);
\node[align=flush left,text width =4cm,
anchor=north west,inner sep=1pt] (qu) {\quest};
\node[align=right,text width =4cm,
anchor=north west,inner sep=1pt] (an) at (qu.south west) {\ans};
\end{tikzpicture}
\end{document}
会给
