Expression</a></span><span> : <span class="keyword">sig</span> ... <span class="keyword">end</span></span></code></div><div class="spec-doc"><p>An expression is a term without let-bindings or function values.</p></div></div><div class="odoc-spec"><div class="spec module" id="module-ExpressionSet" class="anchored"><a href="#module-ExpressionSet" class="anchor"></a><code><span><span class="keyword">module</span> <a href="ExpressionSet/index.html">ExpressionSet</a></span><span> : <span class="keyword">sig</spa