aph/index.html#type-node">Owl_graph.node</a></span> array</span> <span class="arrow">&#45;&gt;</span></span>
  <span><span><span class="type-var">'b</span> array</span> <span class="arrow">&#45;&gt;</span></span>
  <span><span><span class="type-var">'a</span> <a href="../../Owl_graph/index.html#type-node">Owl_graph.node</a></span> array</span> * <span><span class="type-var">'b</span> array</span></span></code></div><div class="spec-doc"><p>remove unuserd iopair from an array of nodes</p></div></div><div cla