amp;optional (delta 1) &amp;environment env)
(multiple-value-bind (vars vals old new cas-form read-form)
(get-cas-expansion place env)
(let ((delta-value (gensym “DELTA”)))
`(let* (,&#64;(mapcar ‘list vars vals)
(,old ,read-form)
(,delta-value ,delta)
(,new (+ ,old ,delta-value)))
(loop until (eq ,old (setf ,old ,cas-form))
do (setf ,new (+ ,old ,delta-value)))
,new))))</p>
<p>EXPERIMENTAL: Interface subject to change.</p>
</div></blockquote>
<div class="section" id="lambda-list">
<span id="lambda-lis