is is usually called the <i>transfer function</i> in Abstract Interpretation terms. <code>node</code> is the node containing the current instruction and <code>idx</code> is the index of the instruction in the node.</p></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-pp_session_name"><a href="#val-pp_session_name" class="anchor"></a><code><span><span class="keyword">val</span> pp_session_name : <span><a href="CFG/Node/index.html#type-t">CFG.Node.t</a> <span class="arrow">&#45;&gt;<