type pars = (qid * term) list (* parameter declarations: name, type *)
-(* environment: line number, parameters, name, type, (transparent?, body) *)
-type environment = (int * pars * qid * term * (bool * term) option) list
+(* entry: line number, parameters, name, type, (transparent?, body) *)
+type entry = int * pars * qid * term * (bool * term) option
+
+type item = entry option