(* Copyright (C) 2000, HELM Team.
 * 
 * This file is part of HELM, an Hypertextual, Electronic
 * Library of Mathematics, developed at the Computer Science
 * Department, University of Bologna, Italy.
 * 
 * HELM is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * HELM is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HELM; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA  02111-1307, USA.
 * 
 * For details, see the HELM World-Wide-Web page,
 * http://cs.unibo.it/helm/.
 *)

type sort =
 | Prop
 | Set
 | Type of int
 | CProp

type implicit_annotation = [ `Closed | `Type | `Hole | `Term ]

type local_context = int * (term list) option         (* shift (0 -> no shift), 
                                                         subst (None means id) *) 
and term =
 | Rel      of int                                    (* DeBruijn index, 1 based         *)
 | Meta     of int * local_context
 | Appl     of term list                              (* arguments                       *)
 | Prod     of string * term * term                     (* binder, source, target          *)
 | Lambda   of string * term * term                     (* binder, source, target          *)
 | LetIn    of string * term * term * term              (* binder, type, term, body        *)
(* Cast \def degenerate LetIn *)
 | Const    of NReference.reference                   (* reference contains indtypeno/constrno *)
 | Sort     of sort                                   (* sort                            *)
 | Implicit of implicit_annotation                    (* ... *)
 | Match    of NReference.reference *                 (* ind. reference,             *)
    term * term *                                     (*  outtype, ind. term   *)
    term list                                         (*  patterns             *)



type context_entry =                            (* A declaration or definition *)
 | Decl of term
 | Def of term * term option                   (* body, type (if known) *)

type hypothesis = string * context_entry               (* None means no more accessible *)

type context = hypothesis list

type conjecture = int * string option * context * term

type metasenv = conjecture list

type substitution = (int * (string option * context * term * term)) list




type inductiveFun =
 string * int * term * term   (* if coinductive, the int has no meaning and must be set to -1 *)

type constructor = string * term                                (* id, type *)

type inductiveType = 
 string * bool * term *       (* typename, inductive, arity *)
 constructor list            (* constructors              *)

type def_flavour = (* presentational *)
  [ `Definition
  | `Fact
  | `Lemma
  | `Remark
  | `Theorem
  ]

type def_pragma = (* pragmatic of the object *)
  [ `Coercion of int
  | `Elim of sort       (** elimination principle; if sort is Type, the universe is not relevant *)
  | `Projection         (** record projection *)
  | `InversionPrinciple (** inversion principle *)
  | `Variant
  ]
 
type ind_pragma = (* pragmatic of the object *)
  [ `Record of (string * bool * int) list (** 
    inductive type that encodes a record; the arguments are
    the record fields names and if they are coercions and
    then the coercion arity *)
  ]

type generated = [ `Generated | `Provided ]

type c_attr = generated * def_flavour * def_pragma
type f_attr = generated * def_flavour
type i_attr = generated * ind_pragma

type obj =
 | Constant  of NUri.uri * metasenv * substitution * string * term option * term * c_attr
 | Fixpoint  of NUri.uri * metasenv * substitution * bool * inductiveFun list * f_attr
 | Inductive of NUri.uri * metasenv * substitution * inductiveType list * i_attr