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