Mark a variable as `old'.
Function:
(defun atj-mark-var-old (var) (declare (xargs :guard (symbolp var))) (let ((__function__ 'atj-mark-var-old)) (declare (ignorable __function__)) (packn-pos (list "[O]" var) var)))
Theorem:
(defthm symbolp-of-atj-mark-var-old (b* ((marked-var (atj-mark-var-old var))) (symbolp marked-var)) :rule-classes :rewrite)