;;; $Id: environments.def,v 1.6 1998/10/16 02:55:55 leavens Exp $ (defrep Environment (ff Denoted-Value)) (deftype the-empty-env Environment) (deftype extend-env (-> ((list symbol) (list Denoted-Value) Environment) Environment)) (deftype apply-env (-> (Environment symbol) Denoted-Value)) (deftype defined-in-env? (-> (Environment symbol) boolean))