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Screen

Screenp

Recognizer for screen structures.

Signature
(screenp x) → *

Definitions and Theorems

Function: screenp

(defun screenp (x)
  (declare (xargs :guard t))
  (let ((__function__ 'screenp))
    (declare (ignorable __function__))
    (and (consp x)
         (eq (car x) :screen)
         (mbe :logic (and (alistp (cdr x))
                          (equal (strip-cars (cdr x))
                                 '(messages)))
              :exec (fty::alist-with-carsp (cdr x)
                                           '(messages)))
         (b* ((messages (cdr (std::da-nth 0 (cdr x)))))
           (screen-message-listp messages)))))

Theorem: consp-when-screenp

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