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Tree

Tree-kind

Get the kind (tag) of a tree structure.

Signature
(tree-kind x) → kind
Arguments: x — Guard (treep x).

Definitions and Theorems

Function: tree-kind$inline

(defun tree-kind$inline (x)
  (declare (xargs :guard (treep x)))
  (let ((__function__ 'tree-kind))
    (declare (ignorable __function__))
    (mbe :logic (cond ((or (atom x) (eq (car x) :leafterm))
                       :leafterm)
                      ((eq (car x) :leafrule) :leafrule)
                      (t :nonleaf))
         :exec (car x))))

Theorem: tree-kind-possibilities

(defthm tree-kind-possibilities
 (or (equal (tree-kind x) :leafterm)
     (equal (tree-kind x) :leafrule)
     (equal (tree-kind x) :nonleaf))
 :rule-classes ((:forward-chaining :trigger-terms ((tree-kind x)))))