 <code>f</code> from the right.</p></dd></dl></details></div></div></div><dl><dt class="spec value" id="val-fold"><a href="#val-fold" class="anchor"></a><code><span class="keyword">val</span> fold : <span>(<span class="keyword">module</span> <a href="../../Alg_structs/Monoid/module-type-S/index.html">Alg_structs.Monoid.S</a> <span class="keyword">with</span> <span class="keyword">type</span> <a href="../../Alg_structs/Monoid/module-type-S/index.html#type-t">t</a> = <span class="type-var">'a</span>)</span> <