# Bracket problem with \newtheorem

\documentclass[a4paper, 11pt, notitlepage]{report}
\usepackage{amsthm}
\theoremstyle{plain}
\newtheorem{thm}{Theorem}[section] % reset theorem numbering for each chapter
\theoremstyle{definition}
\newtheorem{props}[thm]{Proposition}

\begin{document}
\begin{props} [[1], p. 180]
\end{props}
\end{document}


The result would be:

Proposition 0.0.1 ([1). , p. 180]

How do I make it like this:

Proposition 0.0.1 ([1], p. 180)

I'm using TeXStudio with XeLaTeX.

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Just write begin{props} [[1{]}, p. 180] or begin{props} [[{1]}, p. 180]. – Bernard Apr 21 '14 at 10:08
@Bernard - I noticed your comment only after I posted my answer. I've updated the answer to mention your solution. – Mico Apr 21 '14 at 10:19
@Mico: That's nothing. It also happens to me from time to time. What's more important, I think, is your suggestion to use a citation command. – Bernard Apr 21 '14 at 10:29
What's the purpose {} there? Does it work like \ in math mode? Thanks for your answer. – user74158 Apr 21 '14 at 10:40
No, it's only a way to isolate it — for LaTeX there is an ambiguity due to the fact that you use an optional argument that is introduced by a [. That is why, semantically, I prefer to write {[1]} rather than [1{]}, though both work. – Bernard Apr 21 '14 at 11:20

You could load the mathtools package and use its commands \lbrack and \rbrack -- note that they need to be used in math mode -- to typeset square brackets in a way that doesn't trip up LaTeX. I.e., you'd write

\begin{props}[$\lbrack 1\rbrack]$, p.~180]


Addendum: I just noticed the comment posted by @Bernard: An even easier solution is to write

\begin{props}[{[1]}, p.~180]


Presumably, though, the [1] element is a call-out to an entry in the bibliography. Have you tried \begin{props}[\cite{whatever}, p.~180], where "whatever" is the citation key of the entry in question? Assuming you're using a numeric citation style, the \cite command will generate the [1] element for you in a way that doesn't interfere with \begin{props}.

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I wish I could use \cite, but I have problem with that as well: tex.stackexchange.com/questions/172579/… – user74158 Apr 21 '14 at 10:41
@user74158 - I've added some comments at the end of your earlier posting. Please be more specific as to the problems you're encountering. – Mico Apr 21 '14 at 10:56