macros and math mode

Question

I am trying to create two new macros:

braces: compiles some text between curly brackets
squakets: compiles text between two square brackets

I defined as follows.

\documentclass{article}

\newcommand{\braces}[2]{$\left\{\begin{tabular}{@{}c@{}}
    #1\\
    #2\\
    \end{tabular}\right\}$}    


\newcommand{\squakets}[1]{$\Big[ #1 \Big]$}

\begin{document}

\squakets{\squakets{\braces{$\sqrt{}$}{$\alpha$} \braces{$x$}{$\beta$}} \braces{$y$}{$\gamma$}} $\rightarrow$ \braces{$\sqrt{}$}{$\alpha$} -- \braces{$x$}{$\beta$} -- \braces{$y$}{$\gamma$}

\end{document}

Console still compiles, even though it warns me that:

Missing $ inserted.

I was curious of understanding how to fix this. I guess it is something related to the fact I am embedding multiple squakets command in one another, but can someone help figure that out?

You are using the wrong approach here. What solves your problem is \ensuremath{..} rather than $..$ . But still, if it's math, it should be in math mode, and not (ab)use \ensuremath. — Manuel, Jan 28 '18 at 01:22
You cannot nest $...$ . You should either change them to \ensuremath{} or, preferably, remove them. Then use your macro inside math mode only. — Phelype Oleinik, Jan 28 '18 at 01:24

score 1 · Answer 1 · answered Jan 28 '18 at 01:28

1

\documentclass{article}

\usepackage{mleftright}

\newcommand*\braces[2]{\mleft\{{\begingroup#1\endgroup\atop#2}\mright\}}
\newcommand*\squakets[1]{\Bigl[#1\Bigr]}

\begin{document}

\[
  \squakets{\squakets{\braces{\sqrt{}}{\alpha} \braces{x}{\beta}} \braces{y}{\gamma}}
  \to
  \braces{\sqrt{}}{\alpha} - \braces{x}{\beta} - \braces{y}{\gamma}
\]

\end{document}

answered Jan 28 '18 at 01:28

Manuel

27,118

Thank you, @Manuel! However, your solution compiles something a bit different from what I had in mind. – RobertP. Jan 28 '18 at 03:05

score 0 · Answer 2 · answered Jan 28 '18 at 03:05

Thank you for all of your help!

This is the solution I came up with:

\newcommand*{\braces}[2]{\ensuremath{\left\{\begin{tabular}{@{}c@{}}
        #1\\
        #2\\
        \end{tabular}\right\}}}

As suggested in the comments above, \ensuremath{} instead of $...$ solves the issue.

macros and math mode

2 Answers2