+type 'a bag = int (* max ID *)
+ * (('a unit_clause * bool * int) M.t)
+
+(* also gives a fresh ID to the clause *)
+ val add_to_bag :
+ 'a unit_clause -> 'a bag ->
+ 'a bag * 'a unit_clause
+
+ val replace_in_bag :
+ 'a unit_clause * bool * int -> 'a bag ->
+ 'a bag
+
+ val get_from_bag :
+ int -> 'a bag -> 'a unit_clause * bool * int
+
+ val empty_bag : 'a bag
+
+module type Blob =
+ sig
+ (* Blob is the type for opaque leaves:
+ * - checking equlity should be efficient
+ * - atoms have to be equipped with a total order relation
+ *)
+ type t
+ val eq : t -> t -> bool
+ val compare : t -> t -> int
+ val eqP : t
+ (* TODO: consider taking in input an imperative buffer for Format
+ * val pp : Format.formatter -> t -> unit
+ * *)
+ val is_eq : t foterm -> (t foterm * t foterm * t foterm) option
+ val pp : t -> string
+
+ type input
+ val embed : input -> t foterm
+ (* saturate [proof] [type] -> [proof] * [type] *)
+ val saturate : input -> input -> t foterm * t foterm
+
+ end