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Constraint

Constraintp

Recognizer for constraint structures.

Signature
(constraintp x) → *

Definitions and Theorems

Function: constraintp

(defun constraintp (x)
  (declare (xargs :guard t))
  (let ((__function__ 'constraintp))
    (declare (ignorable __function__))
    (and (consp x)
         (cond ((or (atom x) (eq (car x) :equal))
                (and (true-listp (cdr x))
                     (eql (len (cdr x)) 2)
                     (b* ((left (std::da-nth 0 (cdr x)))
                          (right (std::da-nth 1 (cdr x))))
                       (and (expressionp left)
                            (expressionp right)))))
               (t (and (eq (car x) :relation)
                       (and (true-listp (cdr x))
                            (eql (len (cdr x)) 2))
                       (b* ((name (std::da-nth 0 (cdr x)))
                            (args (std::da-nth 1 (cdr x))))
                         (and (stringp name)
                              (expression-listp args)))))))))

Theorem: consp-when-constraintp

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