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Pointer

Pointer-kind

Get the kind (tag) of a pointer structure.

Signature
(pointer-kind x) → kind
Arguments: x — Guard (pointerp x).

Definitions and Theorems

Function: pointer-kind$inline

(defun pointer-kind$inline (x)
  (declare (xargs :guard (pointerp x)))
  (let ((__function__ 'pointer-kind))
    (declare (ignorable __function__))
    (mbe :logic (cond ((or (atom x) (eq (car x) :null)) :null)
                      ((eq (car x) :dangling) :dangling)
                      (t :valid))
         :exec (car x))))

Theorem: pointer-kind-possibilities

(defthm pointer-kind-possibilities
  (or (equal (pointer-kind x) :null)
      (equal (pointer-kind x) :dangling)
      (equal (pointer-kind x) :valid))
  :rule-classes
  ((:forward-chaining :trigger-terms ((pointer-kind x)))))