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Literal

Literalp

Recognizer for literal structures.

Signature
(literalp x) → *

Definitions and Theorems

Function: literalp

(defun literalp (x)
  (declare (xargs :guard t))
  (let ((__function__ 'literalp))
    (declare (ignorable __function__))
    (and (consp x)
         (cond ((or (atom x) (eq (car x) :boolean))
                (and (true-listp (cdr x))
                     (eql (len (cdr x)) 1)
                     (b* ((value (std::da-nth 0 (cdr x))))
                       (booleanp value))))
               ((eq (car x) :character)
                (and (true-listp (cdr x))
                     (eql (len (cdr x)) 1)
                     (b* ((value (std::da-nth 0 (cdr x))))
                       (characterp value))))
               ((eq (car x) :string)
                (and (true-listp (cdr x))
                     (eql (len (cdr x)) 1)
                     (b* ((value (std::da-nth 0 (cdr x))))
                       (stringp value))))
               (t (and (eq (car x) :integer)
                       (and (true-listp (cdr x))
                            (eql (len (cdr x)) 1))
                       (b* ((value (std::da-nth 0 (cdr x))))
                         (natp value))))))))

Theorem: consp-when-literalp

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