Get the pat field from a regex-zerolength.
This is an ordinary field accessor created by defprod.
Function:
(defun regex-zerolength->pat$inline (x) (declare (xargs :guard (regex-p x))) (declare (xargs :guard (equal (regex-kind x) :zerolength))) (let ((__function__ 'regex-zerolength->pat)) (declare (ignorable __function__)) (mbe :logic (b* ((x (and (equal (regex-kind x) :zerolength) x))) (regex-fix (std::da-nth 0 (cdr x)))) :exec (std::da-nth 0 (cdr x)))))
Theorem:
(defthm regex-p-of-regex-zerolength->pat (b* ((pat (regex-zerolength->pat$inline x))) (regex-p pat)) :rule-classes :rewrite)
Theorem:
(defthm regex-zerolength->pat$inline-of-regex-fix-x (equal (regex-zerolength->pat$inline (regex-fix x)) (regex-zerolength->pat$inline x)))
Theorem:
(defthm regex-zerolength->pat$inline-regex-equiv-congruence-on-x (implies (regex-equiv x x-equiv) (equal (regex-zerolength->pat$inline x) (regex-zerolength->pat$inline x-equiv))) :rule-classes :congruence)
Theorem:
(defthm regex-zerolength->pat-when-wrong-kind (implies (not (equal (regex-kind x) :zerolength)) (equal (regex-zerolength->pat x) (regex-fix nil))))