">'a</span> <a href="#type-t">t</a></span> <span class="arrow">&#45;&gt;</span></span> <span><span><span class="type-var">'a</span> <a href="#type-t">t</a></span> <span class="arrow">&#45;&gt;</span></span> <span><span class="type-var">'a</span> <a href="#type-t">t</a></span></span></code></div><div class="spec-doc"><p><code>union_absent m1 m2</code> contains all the bindings of <code>m1</code> as well as those of <code>m2</code> for keys not contained by <code>m1</code>. <code>union_absent m1 m2 == m1</cod