val empty_kam: kam
-val get: (unit -> 'a) -> (Brg.bind -> 'a) -> kam -> int -> 'a
+val get: kam -> int -> Brg.bind
-val push: kam -> Brg.bind -> kam
+val push: kam -> Entity.attrs -> Brg.bind -> kam
val xwhd: Entity.status -> kam -> Brg.term -> kam * Brg.term