Fixer for pass.
Function:
(defun pass-fix (x) (declare (xargs :guard (passp x))) (mbe :logic (if (passp x) x :pass) :exec x))
Theorem:
(defthm passp-of-pass-fix (b* ((fixed-x (pass-fix x))) (passp fixed-x)) :rule-classes :rewrite)
Theorem:
(defthm pass-fix-when-passp (implies (passp x) (equal (pass-fix x) x)))