type document =
  Nethtml.document =
    Element of (string * (string * string) list * document list)
  | Data of string
type element_class =
    [ `Block | `Essential_block | `Everywhere | `Inline | `None ]
type model_constraint =
    [ `Any
    | `Block
    | `Elements of string list
    | `Empty
    | `Except of model_constraint * model_constraint
    | `Flow
    | `Inline
    | `Or of model_constraint * model_constraint
    | `Special
    | `Sub_exclusions of string list * model_constraint ]
type simplified_dtd = (string * (element_class * model_constraint)) list
val html40_dtd : simplified_dtd
val relaxed_html40_dtd : simplified_dtd
val parse_document :
  ?dtd:simplified_dtd ->
  ?return_declarations:bool ->
  ?return_pis:bool -> ?return_comments:bool -> Lexing.lexbuf -> document list
val parse :
  ?dtd:simplified_dtd ->
  ?return_declarations:bool ->
  ?return_pis:bool ->
  ?return_comments:bool -> Netchannels.in_obj_channel -> document list
val decode :
  ?enc:Netconversion.encoding ->
  ?subst:(int -> string) ->
  ?entity_base:[ `Empty | `Html | `Xml ] ->
  ?lookup:(string -> string) -> document list -> document list
val encode :
  ?enc:Netconversion.encoding ->
  ?prefer_name:bool -> document list -> document list
val map_list : (string -> string) -> document list -> document list
val write :
  ?dtd:simplified_dtd -> Netchannels.out_obj_channel -> document list -> unit