module type Gen_set =sig..end
type 'a t 
type 'a bound 
type 'a interval 
val create : ('a bound * 'a bound) list ->
       'a tval create_from_intervals : 'a interval list -> 'a tval contains : 'a t -> 'a bound -> boolval contains_set : container:'a t ->
       contained:'a t -> boolval ubound_exn : 'a t -> 'a boundval lbound_exn : 'a t -> 'a boundval ubound : 'a t -> 'a bound optionval lbound : 'a t -> 'a bound option