Figure with long list of predicates and conjunctions (\wedge)

Question

I have a figure with a long list of predicates connected with \wedge, here is the code:

\begin{figure}[h]               
    \small{     
    $
    Defined\_in(subject\_state, concrete\_subject) \wedge Defined\_in (observer\_state, concrete\_observer) \wedge
    Defined\_in(attach, subject) \wedge Defined\_in(detach, subject) \wedge Defined\_in(notify, subject) \wedge ... it continues ...
    $
    }
    \caption{Caption text}
    \label{fig:myfig}
\end{figure}

the problem is that the output produced by pdflatex is rather ugly:

what I would like is to align it all to left, which I think will look better. If I use \[ and \] instead of $, latex places all the content on one line which overlaps from the page. I would like to avoid manual inserting of new lines with \\, and rather let latex to break it up into lines and align it to left.

Answer 1

% In the preamble
\usepackage{amsmath}
\newcommand{\func}{\textit}
\newcommand{\var}{\textit}

% In the document
\begin{figure}
\small
\begin{align*}
&\func{Defined\_in}(\var{subject\_state}, \var{concrete\_subject}) \wedge {}\\
&\func{Defined\_in}(\var{observer\_state}, \var{concrete\_observer}) \wedge {}\\
&\func{Defined\_in}(\var{attach}, \var{subject}) \wedge {}\\
&\func{Defined\_in}(\var{detach}, \var{subject}) \wedge {}\\
&\func{Defined\_in}(\var{notify}, \var{subject}) \wedge {}\\
...
\end{align*}
\caption{Caption text}
\label{fig:myfig}
\end{figure}

It's way better to use \textit{Defined\_in} instead of simply Defined\_in in math mode as you will see immediately. I propose to distinguish functions from variables, so that you may change their formatting just by modifying the definition of \func or \var.

Just erase {}\\& if you want to merge two lines.

A "beginner's definition" for \func would be

\newcommand{\func}[1]{\textit{#1}}

but definitions such as this one waste time reading the argument twice.

Answer 2

You seem to be writing code; if this is the case, then perhaps you should consider using the listings package; refer to the package documentation to learn all the possibilities it offers. Here's a very simple configuration for your example code:

\documentclass{article}
\usepackage{listings}

\lstset{escapeinside=||,%
  linewidth=\textwidth,%
  basicstyle=\small,%
  breaklines%
}

\begin{document}

\begin{lstlisting}[frame=single,captionpos=top,caption={Caption text},label=myalg]               
Defined_in(subject_state,concrete_subject) |$\wedge$|
Defined_in(observer_state,concrete_observer) |$\wedge$|
Defined_in(attach,subject) |$\wedge$| Defined_in(detach,subject) |$\wedge$|
Defined_in(notify,subject) |$\wedge$|
\end{lstlisting}

\end{document}

EDIT: If you want automatic line-breaking in dsiplayed math, you could give the breqn package a try; here's a little example using the definitions of egreg's answer:

\documentclass{article}
\usepackage{breqn}

\newcommand{\func}{\textit}
\newcommand{\var}{\textit}

\begin{document}

\begin{figure}
\small
\begin{dmath*}
\func{Defined\_in}(\var{subject\_state}, \var{concrete\_subject}) \wedge\func{Defined\_in}(\var{observer\_state}, \var{concrete\_observer}) \wedge\func{Defined\_in}(\var{attach}, \var{subject}) \wedge\func{Defined\_in}(\var{detach}, \var{subject}) \wedge\func{Defined\_in}(\var{notify}, \var{subject}) \wedge ...
\end{dmath*}
\caption{Caption text}
\label{fig:myfig}
\end{figure}

\end{document}

The result: