		Search-engine friendly clone of the ACL2 documentation.

Hex-quad

Hex-quad->4th

Get the 4th field from a hex-quad.

Signature
(hex-quad->4th x) → 4th
Arguments: x — Guard (hex-quad-p x).
Returns: 4th — Type (hex-digit-char-p 4th).

This is an ordinary field accessor created by fty::defprod.

Definitions and Theorems

Function: hex-quad->4th$inline

(defun hex-quad->4th$inline (x)
  (declare (xargs :guard (hex-quad-p x)))
  (declare (xargs :guard t))
  (let ((__function__ 'hex-quad->4th))
    (declare (ignorable __function__))
    (mbe :logic
         (b* ((x (and t x)))
           (str::hex-digit-char-fix (cdr (std::da-nth 3 x))))
         :exec (cdr (std::da-nth 3 x)))))

Theorem: hex-digit-char-p-of-hex-quad->4th

(defthm hex-digit-char-p-of-hex-quad->4th
  (b* ((4th (hex-quad->4th$inline x)))
    (hex-digit-char-p 4th))
  :rule-classes :rewrite)

Theorem: hex-quad->4th$inline-of-hex-quad-fix-x

(defthm hex-quad->4th$inline-of-hex-quad-fix-x
  (equal (hex-quad->4th$inline (hex-quad-fix x))
         (hex-quad->4th$inline x)))

Theorem: hex-quad->4th$inline-hex-quad-equiv-congruence-on-x

(defthm hex-quad->4th$inline-hex-quad-equiv-congruence-on-x
  (implies (hex-quad-equiv x x-equiv)
           (equal (hex-quad->4th$inline x)
                  (hex-quad->4th$inline x-equiv)))
  :rule-classes :congruence)