span class="type-var">'b</span>)</span> <a href="../argument-1-A/index.html#type-t">A.t</a></span> <span>&#45;&gt;</span> <span><span class="type-var">'a</span> <a href="../argument-1-A/index.html#type-t">A.t</a></span> <span>&#45;&gt;</span> bool</code></dt><dt class="spec value" id="val-annihalation"><a href="#val-annihalation" class="anchor"></a><code><span class="keyword">val</span> annihalation : <span><span>(<span class="type-var">'a</span> <span>&#45;&gt;</span> <span class="type-var">'b</span>)</spa