Writing Linear Temporal Logic in LaTeX

Here are some useful symbols

\documentclass{article}
\usepackage{amsmath,amssymb}
\pagestyle{empty}
\begin{document}
\renewcommand{\arraystretch}{2}

\begin{tabular}[t]{rl|rl}%
      \verb=\lnot=   & $ \lnot $ & \\
      \verb=\square= & $\square$ & \verb=\lozenge= & $\lozenge$ \\
      \verb=\vee=    & $\vee $   & \verb=\wedge=   & $\wedge$  \\
      \verb=\vdash=  & $\vdash$  & \verb=\models=  & $\models$ \\
\end{tabular}

\end{document}

Applying DRY to A.Ellet's answer.

\documentclass[preview]{standalone}
\usepackage{amsmath,amssymb}

\renewcommand{\arraystretch}{2}

\def\x#1{\texttt{\expandafter\string\csname#1\endcsname}&\expandafter$\csname#1\endcsname$}


\begin{document}
\begin{tabular}[t]{rl|rl}%
    \x{lnot}    & \multicolumn{2}{c}{none}\\
    \x{square}  & \x{lozenge}\\
    \x{vee}     & \x{wedge}\\
    \x{vdash}   & \x{models}\\
\end{tabular}
\end{document}

There is the LTLfonts LaTeX package from Stanford, which provides commands and fonts for Linear Temporal Logic.

There is a more recent ltl LaTeX package (work in progress of this post) supporting both the letter operators F,G,etc. and the symbol operators <>,[], etc. Note that this package includes the previous as an option.

There is the circle package on CTAN, providing an improved symbol for the next operator.