sig
type env = InnerTerm.t DBEnv.t
val closed : InnerTerm.t -> bool
val contains : InnerTerm.t -> int -> bool
val shift : int -> InnerTerm.t -> InnerTerm.t
val unshift : int -> InnerTerm.t -> InnerTerm.t
val replace : InnerTerm.t -> sub:InnerTerm.t -> InnerTerm.t
val from_var : InnerTerm.t -> var:InnerTerm.t -> InnerTerm.t
val eval : InnerTerm.DB.env -> InnerTerm.t -> InnerTerm.t
val apply_subst :
InnerTerm.t InnerTerm.VarMap.t -> InnerTerm.t -> InnerTerm.t
end