Get the previous field from a certificate.
(certificate->previous x) → previous
This is an ordinary field accessor created by fty::defprod.
Function:
(defun certificate->previous$inline (x) (declare (xargs :guard (certificatep x))) (declare (xargs :guard t)) (let ((__function__ 'certificate->previous)) (declare (ignorable __function__)) (mbe :logic (b* ((x (and t x))) (address-set-fix (cdr (std::da-nth 3 x)))) :exec (cdr (std::da-nth 3 x)))))
Theorem:
(defthm address-setp-of-certificate->previous (b* ((previous (certificate->previous$inline x))) (address-setp previous)) :rule-classes :rewrite)
Theorem:
(defthm certificate->previous$inline-of-certificate-fix-x (equal (certificate->previous$inline (certificate-fix x)) (certificate->previous$inline x)))
Theorem:
(defthm certificate->previous$inline-certificate-equiv-congruence-on-x (implies (certificate-equiv x x-equiv) (equal (certificate->previous$inline x) (certificate->previous$inline x-equiv))) :rule-classes :congruence)