Listing 3. wrap.php


function wrap($thunk) {
  return <<<EOS
    \documentclass[10pt]{article}

    % add additional packages here
    \usepackage{amsmath}
    \usepackage{amsfonts}
    \usepackage{amssymb}
    \usepackage{pst-plot}
    \usepackage{color}

    \pagestyle{empty}
    \begin{document}
    $thunk
    \end{document}
EOS;
}