Command lines
val (%) : t -> string -> t
val add_arg : t -> string -> t
val add_args : t -> t -> t
val equal : t -> t -> bool
val compare : t -> t -> int
val to_rev_list : t -> string list
val to_list : t -> string list
val of_list : ?slip:string -> string list -> t
val dump : Stdlib.Format.formatter -> t -> unit