		Search-engine friendly clone of the ACL2 documentation.

Sandwich

Sandwich-p

Recognizer for sandwich structures.

Signature
(sandwich-p x) → *

Definitions and Theorems

Function: sandwich-p

(defun sandwich-p (x)
  (declare (xargs :guard t))
  (let ((acl2::__function__ 'sandwich-p))
    (declare (ignorable acl2::__function__))
    (and (mbe :logic (and (alistp x)
                          (equal (strip-cars x)
                                 '(bread fillings)))
              :exec (fty::alist-with-carsp x '(bread fillings)))
         (b* ((bread (cdr (std::da-nth 0 x)))
              (fillings (cdr (std::da-nth 1 x))))
           (and (integerp bread)
                (symbolp fillings))))))

Theorem: consp-when-sandwich-p

(defthm consp-when-sandwich-p
  (implies (sandwich-p x) (consp x))
  :rule-classes :compound-recognizer)