><code><span class="keyword">val</span> diff : <span><span class="type-var">'a</span> option</span></code></dt><dt class="spec value" id="val-filter"><a href="#val-filter" class="anchor"></a><code><span class="keyword">val</span> filter : <span>Oct.t <a href="index.html#module-A">A</a>.t</span> <span>&#45;&gt;</span> Apronext__.Tconsext.t <span>&#45;&gt;</span> <span><span>Oct.t <a href="index.html#module-A">A</a>.t</span> <a href="../../Libabsolute/Consistency/index.html#type-t">Libabsolute.Consistency.t</