w">&#45;&gt;</span></span>
  <span><a href="../../ProcCfg/InstrNode/index.html#type-instr_index">ProcCfg.InstrNode.instr_index</a> <span class="arrow">&#45;&gt;</span></span>
  <span><a href="#type-instr">instr</a> <span class="arrow">&#45;&gt;</span></span>
  <a href="Domain/index.html#type-t">Domain.t</a></span></code></div><div class="spec-doc"><p><code>exec_instr astate proc_data node idx instr</code> should usually return <code>astate'</code> such that <code>{astate} instr {astate'}</code> is a valid H