Gsl_combitype t = private {n : int;k : int;data : (int, Bigarray.int_elt, Bigarray.c_layout) Bigarray.Array1.t;}val _init_first : t -> unitval _init_last : t -> unitval make : int -> int -> tval to_array : t -> int arrayval prev : t -> unitval next : t -> unitval valid : t -> bool