Detect width of minipage environment

Question

I am using the following setup to add comments to the right of aligned equations.

\documentclass{amsart}
\usepackage{lipsum}

\newcommand{\comment}[1]{\text{\footnotesize{#1}}}
\newcommand{\blurb}[2]{\begin{minipage}{#1} \footnotesize #2 \end{minipage}}


\begin{document}

\lipsum[1]

\begin{align*}
1 &= 2 \\
3 &= 4 && \comment{\lipsum[1]} \\
5 &= 6 && \blurb{4in}{\lipsum[1]}
\end{align*}

\end{document}

It produces the following:

Currently, if I have a comment that is too long to keep the equation group within the text width (as in the comment for $3 = 4$), I use the blurb command I defined and manually tweak the minipage width until it's acceptable (as in the comment for $5=6$). (Maybe a better criterion for "acceptable" would be the largest minipage width that allows the entire equation group to sit within the text width; this is often what I end up doing because of space constraints with long equations and comments.)

Is there some automation so that I don't have to manually tweak my too-long comments to blurbs? A solution as described in the question title seems unlikely because it would need a width parameter to define a minipage, but the contents of the minipage determine what that width parameter should be. But maybe there's another way to achieve the same result.

In my opinion, you should use wide lengthy comments on the side of the equations This makes the body of the equations flush left, which doesn't look very good. You should the \intertext{…} or \shortintertex{…} instead. — Bernard, Aug 31 '16 at 00:20
...as seen in How can I add left aligned text to an equation? and Adding line by line comments to math proofs. — Werner, Aug 31 '16 at 00:22
The main problem is that LaTeX doesn't know how wide the remainder is until after the comment is formatted. You could use \tikzmark and pgfpagenodes to compute the width using two runs. — John Kormylo, Aug 31 '16 at 14:52

Detect width of minipage environment

0 Answers0