<span><span class="exception">Syntax_error</span> <span class="keyword">of</span> string</span></code></div><div class="spec-doc"><p><code>Syntax_error</code> is raised when the parser encounters a parsing error. It should include the problem character</p></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-simplify"><a href="#val-simplify" class="anchor"></a><code><span><span class="keyword">val</span> simplify : <span><a href="../Tree/index.html#type-re">Tree.re</a> <span class="arr