include Types.PREMONAD with type 'a t = 'a Stdlib.ref
include Types.UNARY_TYPE with type 'a t = 'a Stdlib.ref
type 'a t = 'a Stdlib.ref
val compare : ('a -> 'a -> int) -> 'a t -> 'a t -> int
val equal : ('a -> 'a -> bool) -> 'a t -> 'a t -> bool
val hash : ('a -> int) -> 'a t -> int
val map : ('a -> 'b) -> 'a t -> 'b t
val iter : ('a -> unit) -> 'a t -> unit
val fold : ('a -> 'b -> 'b) -> 'a t -> 'b -> 'b
val bind : ('a -> 'b t) -> 'a t -> 'b t
val join : 'a t t -> 'a t