		Search-engine friendly clone of the ACL2 documentation.

Hex-pair

Hex-pairp

Recognizer for hex-pair structures.

Signature
(hex-pairp x) → *

Definitions and Theorems

Function: hex-pairp

(defun hex-pairp (x)
  (declare (xargs :guard t))
  (let ((__function__ 'hex-pairp))
    (declare (ignorable __function__))
    (and (consp x)
         (eq (car x) :hex-pair)
         (mbe :logic (and (alistp (cdr x))
                          (equal (strip-cars (cdr x)) '(1st 2nd)))
              :exec (fty::alist-with-carsp (cdr x)
                                           '(1st 2nd)))
         (b* ((1st (cdr (std::da-nth 0 (cdr x))))
              (2nd (cdr (std::da-nth 1 (cdr x)))))
           (and (hex-digitp 1st)
                (hex-digitp 2nd))))))

Theorem: consp-when-hex-pairp

(defthm consp-when-hex-pairp
  (implies (hex-pairp x) (consp x))
  :rule-classes :compound-recognizer)