</p><div class="variablelist"><dl><dt><span class="term">Pre-conditions:</span></dt><dd><p>None.</p></dd><dt><span class="term">Action:</span></dt><dd><p>It finds all the occurrences of <span><strong class="command">t</strong></span>
(possibly applied to arguments) in the subterms matched by
<span><strong class="command">patt</strong></span>. Then it δ-expands each occurrence,
</p><div class="variablelist"><dl><dt><span class="term">Pre-conditions:</span></dt><dd><p>None.</p></dd><dt><span class="term">Action:</span></dt><dd><p>It finds all the occurrences of <span><strong class="command">t</strong></span>
(possibly applied to arguments) in the subterms matched by
<span><strong class="command">patt</strong></span>. Then it δ-expands each occurrence,