d">val</span> plus : <a href="index.html#type-t">t</a> <span>&#45;&gt;</span> <a href="index.html#type-t">t</a> <span>&#45;&gt;</span> <a href="index.html#type-t">t</a></code></dt><dd><p>Union of two maps where common costs are added together</p></dd></dl><dl><dt class="spec value" id="val-unit_cost_atomic_operation"><a href="#val-unit_cost_atomic_operation" class="anchor"></a><code><span class="keyword">val</span> unit_cost_atomic_operation : <a href="index.html#type-t">t</a></code></dt><dd><p>Map represen