+(defun xep-tail-combination-p (node)
+ (and (combination-p node)
+ (let* ((lvar (combination-lvar node))
+ (dest (when (lvar-p lvar) (lvar-dest lvar)))
+ (lambda (when (return-p dest) (return-lambda dest))))
+ (and (lambda-p lambda)
+ (eq :external (lambda-kind lambda))))))
+