val create_session : string -> session_id
+val get_session_owner : session_id -> string
+
val get_status : session_id -> MatitaEngine.status
val get_history : session_id -> MatitaEngine.status list
val set_history : session_id -> MatitaEngine.status list -> unit
-val logout_user : string -> unit
+val logout_user : session_id -> unit
val remove_user : string -> unit