		Search-engine friendly clone of the ACL2 documentation.

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) :integer))
                (and (true-listp (cdr x))
                     (eql (len (cdr x)) 1)
                     (b* ((get (std::da-nth 0 (cdr x))))
                       (integer-literalp get))))
               ((eq (car x) :fpoint)
                (and (true-listp (cdr x))
                     (eql (len (cdr x)) 1)
                     (b* ((get (std::da-nth 0 (cdr x))))
                       (floating-point-literalp get))))
               ((eq (car x) :char)
                (and (true-listp (cdr x))
                     (eql (len (cdr x)) 1)
                     (b* ((get (std::da-nth 0 (cdr x))))
                       (char-literalp get))))
               ((eq (car x) :string)
                (and (true-listp (cdr x))
                     (eql (len (cdr x)) 1)
                     (b* ((get (std::da-nth 0 (cdr x))))
                       (string-literalp get))))
               ((eq (car x) :boolean)
                (and (true-listp (cdr x))
                     (eql (len (cdr x)) 1)
                     (b* ((get (std::da-nth 0 (cdr x))))
                       (booleanp get))))
               (t (and (eq (car x) :null)
                       (and (true-listp (cdr x))
                            (eql (len (cdr x)) 0))
                       (b* nil t)))))))

Theorem: consp-when-literalp

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