Variables and Bindings: You Get for Free!
(defun variable-p (thing) ...)
(defun binding-p (thing) ...)
(defun make-binding (var const) ...)
(defun binding-var (binding) ...)
(defun binding-bdg (binding) ...)
(defun binding-list-p (thing) ...)
(defun make-empty-binding-list ( ) ...)
(defun get-binding (var binding-list) ...)
(defun add-binding (binding binding-list) ...)