tml#introduction-2"><i class="fa fa-check"></i><b>5.1</b> Introduction</a></li>
<li class="chapter" data-level="5.2" data-path="ch-validity.html"><a href="ch-validity.html#sec:causality"><i class="fa fa-check"></i><b>5.2</b> Causality</a></li>
<li class="chapter" data-level="5.3" data-path="ch-validity.html"><a href="ch-validity.html#sec:validity"><i class="fa fa-check"></i><b>5.3</b> Validity</a></li>
<li class="chapter" data-level="5.4" data-path="ch-validity.html"><a href="ch-validity.html#sec:internalva