sig val length : 'a list -> int val hd : 'a list ->'a val tl : 'a list ->'a list val nth : 'a list -> int ->'a val rev : 'a list ->'a list val append : 'a list ->'a list ->'a list val rev_append : 'a list ->'a list ->'a list val concat : 'a list list ->'a list val flatten : 'a list list ->'a list val iter : ('a -> unit) ->'a list -> unit val map : ('a ->'b) ->'a list ->'b list val rev_map : ('a ->'b) ->'a list ->'b list val fold_left : ('a ->'b ->'a) ->'a ->'b list ->'a val fold_right : ('a ->'b ->'b) ->'a list ->'b ->'b val iter2 : ('a ->'b -> unit) ->'a list ->'b list -> unit val map2 : ('a ->'b ->'c) ->'a list ->'b list ->'c list val rev_map2 : ('a ->'b ->'c) ->'a list ->'b list ->'c list val fold_left2 : ('a ->'b ->'c ->'a) ->'a ->'b list ->'c list ->'a val fold_right2 : ('a ->'b ->'c ->'c) ->'a list ->'b list ->'c ->'c val for_all : ('a -> bool) ->'a list -> bool val exists : ('a -> bool) ->'a list -> bool val for_all2 : ('a ->'b -> bool) ->'a list ->'b list -> bool val exists2 : ('a ->'b -> bool) ->'a list ->'b list -> bool val mem : 'a ->'a list -> bool val memq : 'a ->'a list -> bool val find : ('a -> bool) ->'a list ->'a val filter : ('a -> bool) ->'a list ->'a list val find_all : ('a -> bool) ->'a list ->'a list val partition : ('a -> bool) ->'a list ->'a list * 'a list val assoc : 'a -> ('a * 'b) list ->'b val assq : 'a -> ('a * 'b) list ->'b val mem_assoc : 'a -> ('a * 'b) list -> bool val mem_assq : 'a -> ('a * 'b) list -> bool val remove_assoc : 'a -> ('a * 'b) list -> ('a * 'b) list val remove_assq : 'a -> ('a * 'b) list -> ('a * 'b) list val split : ('a * 'b) list ->'a list * 'b list val combine : 'a list ->'b list -> ('a * 'b) list val sort : ('a ->'a -> int) ->'a list ->'a list val stable_sort : ('a ->'a -> int) ->'a list ->'a list val fast_sort : ('a ->'a -> int) ->'a list ->'a list val merge : ('a ->'a -> int) ->'a list ->'a list ->'a list
