n></span> string</span></code></div><div class="spec-doc"><p><code>export_graphviz r</code></p><ul class="at-tags"><li class="returns"><span class="at-tag">returns</span> <p>a representation of the Abstract Syntax Tree representing <code>r</code> in the DOT language for Graphviz</p></li></ul></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-get_alphabet"><a href="#val-get_alphabet" class="anchor"></a><code><span><span class="keyword">val</span> get_alphabet : <span><a href="../Tree