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Backref

Backref-p

Recognizer for backref structures.

Signature
(backref-p x) → *

Definitions and Theorems

Function: backref-p

(defun backref-p (x)
  (declare (xargs :guard t))
  (let ((__function__ 'backref-p))
    (declare (ignorable __function__))
    (and (std::prod-consp x)
         (b* ((loc (std::prod-car x))
              (len (std::prod-cdr x)))
           (and (natp loc) (natp len))))))

Theorem: consp-when-backref-p

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