Variables in scope for the old code in variable renaming.
(varset-old ren) → varset
This explicates the fact that, as mentioned in renaming-variables, the keys of a renaming alist are the variables in scope for the old code.
Also see varset-new.
Function:
(defun varset-old (ren) (declare (xargs :guard (renamingp ren))) (let ((__function__ 'varset-old)) (declare (ignorable __function__)) (mergesort (strip-cars (renaming->list ren)))))
Theorem:
(defthm identifier-setp-of-varset-old (b* ((varset (varset-old ren))) (identifier-setp varset)) :rule-classes :rewrite)
Theorem:
(defthm varset-old-of-renaming-fix-ren (equal (varset-old (renaming-fix ren)) (varset-old ren)))
Theorem:
(defthm varset-old-renaming-equiv-congruence-on-ren (implies (renaming-equiv ren ren-equiv) (equal (varset-old ren) (varset-old ren-equiv))) :rule-classes :congruence)