ype-t">t</a> <span class="arrow">&#45;&gt;</span></span> bool</span></code></div><div class="spec-doc"><p>It checks if a pvar in location satisfies <code>f</code>.</p></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-exists_str"><a href="#val-exists_str" class="anchor"></a><code><span><span class="keyword">val</span> exists_str : <span><span class="label">f</span>:<span>(<span>string <span class="arrow">&#45;&gt;</span></span> bool)</span> <span class="arrow">&#45;&gt;</span></span