Get the kind (tag) of a reference structure.
(reference-kind x) → kind
Function:
(defun reference-kind$inline (x) (declare (xargs :guard (referencep x))) (let ((__function__ 'reference-kind)) (declare (ignorable __function__)) (mbe :logic (cond ((or (atom x) (eq (car x) :internal)) :internal) (t :external)) :exec (car x))))
Theorem:
(defthm reference-kind-possibilities (or (equal (reference-kind x) :internal) (equal (reference-kind x) :external)) :rule-classes ((:forward-chaining :trigger-terms ((reference-kind x)))))