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Feat

Featp

Recognizer for feat structures.

Signature
(featp x) → *

Definitions and Theorems

Function: featp

(defun featp (x)
  (declare (xargs :guard t))
  (let ((__function__ 'featp))
    (declare (ignorable __function__))
    (and (mbe :logic (and (alistp x)
                          (equal (strip-cars x) '(base endian m)))
              :exec (fty::alist-with-carsp x '(base endian m)))
         (b* ((base (cdr (std::da-nth 0 x)))
              (endian (cdr (std::da-nth 1 x)))
              (m (cdr (std::da-nth 2 x))))
           (and (feat-basep base)
                (feat-endianp endian)
                (booleanp m))))))

Theorem: consp-when-featp

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