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Rule

Rulep

Recognizer for rule structures.

Signature
(rulep x) → *

Definitions and Theorems

Function: rulep

(defun rulep (x)
  (declare (xargs :guard t))
  (let ((__function__ 'rulep))
    (declare (ignorable __function__))
    (and (consp x)
         (eq (car x) :rule)
         (true-listp (cdr x))
         (eql (len (cdr x)) 3)
         (b* ((name (std::da-nth 0 (cdr x)))
              (incremental (std::da-nth 1 (cdr x)))
              (definiens (std::da-nth 2 (cdr x))))
           (and (rulenamep name)
                (booleanp incremental)
                (alternationp definiens))))))

Theorem: consp-when-rulep

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