# Lists inside ams proofs

I'm using amsart. I'm really annoyed that when I put a list inside a proof (and use a mark for the list), it is indented more than it should be. This is probably because the proof environment is implemented as a trivlist, and sublists often get more indentation.

But the question is what do I do about it? I don't want to re-implement the proof environment... I may not get the details exactly the same.

\documentclass{amsart}
\begin{document}

\begin{list}{Mark}{}
\item Hi
\end{list}

\begin{proof}\
\begin{list}{Mark}{}
\item Hi
\end{list}
\end{proof}

\end{document}

-
You know, I never even noticed this. I guess I don't ever use lists outside proofs. +1 for that. –  Ryan Reich Jun 25 '11 at 15:28

You can redefine the \leftmargin length:

\begin{proof}\mbox{}
\begin{list}{Mark}{\setlength\leftmargin{1.2em}}
\item Hi
\end{list}
\end{proof}


Using the enumitem package, you can define your own customized list that will behave consistently throughout the document:

\documentclass{amsart}
\usepackage{enumitem}

\newlist{mylist}{enumerate}{5}
\setlist[mylist]{label=\arabic*}

\begin{document}

\begin{mylist}
\item Hi
\end{mylist}

\begin{proof}\mbox{}
\begin{mylist}
\item Hi
\end{mylist}
\end{proof}

\end{document}


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(Sorry; I wrote something incorrect because I'd misread the answer, and although I can edit my comment I can't seem to totally delete it. Please just ignore me...) –  Phil Hirschhorn Jun 25 '11 at 20:44
This solution is problematic because the number, 1.2em, depends on the size of the "Mark" characters. It also depends on whether or not you're in a proof. So it's not like I can just redefine the list environment and everything will work out. –  sam Jun 26 '11 at 4:04
@sam: see my updated answer. –  Gonzalo Medina Jun 26 '11 at 12:31
This totally works. Thanks!! Let me wait another day to see if anyone finds a short, non-package solution before accepting this one. –  sam Jun 27 '11 at 4:07
I should mention that the ordinary "enumerate" environment works too. It's only the general "list" that I think has the problem. –  sam Jun 27 '11 at 13:20

when using amsthm, if you want the list to begin on a new line, then follow the \begin command for the proof environment by \leavevmode.

if instead you want to start the list on the same line as the heading, this is the recommended way, adjusting the space between the heading and the first item:

\begin{proof}[<optional modifier>]
\hangindent\leftmargini
\textup{(1)}\hskip\labelsep First item. Provide a long text
to show what happens when there is more than one line.
\begin{enumerate}
\setcounter{enumi}{1}
\item Second
\end{enumerate}
\end{proof}


this works as well with any theorem-class object.

since this is basically a kludge, the topic is on the list of things to be considered the next time an upgrade is undertaken.

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This seems to be answering a different question---that of whether to start lists on the same line as an environment or the next, and how to do it. My question concerned lists anywhere inside a proof (and their behavior being different from outside). –  sam Jun 27 '11 at 4:05
@sam -- thanks for the clarification. you're correct that the answer addresses lists beginning a proof environment. however, i was unaware that lists further inside the environment behaved any differently than they do outside, and i've looked at a lot of them. please send a minimal working example to tech-support@ams.org; we will take a look and enter a bug report as appropriate. –  barbara beeton Jun 27 '11 at 12:10
Oh, cool. There's a working example in the original question; I'll send it to ams too. –  sam Jun 27 '11 at 13:15