(* Copyright (C) 2004, 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://helm.cs.unibo.it/
 *)

type location = int * int

type binder_kind = [ `Lambda | `Pi | `Exists | `Forall ]
type induction_kind = [ `Inductive | `CoInductive ]
type sort_kind = [ `Prop | `Set | `Type | `CProp ]

type term_attribute =
  [ `Loc of location  (* source file location *)
  | `IdRef of string  (* ACic pointer *)
  ]

type term =
  | AttributedTerm of term_attribute * term

  | Appl of term list
  | Binder of binder_kind * capture_variable * term (* kind, name, body *)
  | Case of term * string option * term option * (case_pattern * term) list
      (* what to match, inductive type, out type, <pattern,action> list *)
  | LetIn of capture_variable * term * term  (* name, body, where *)
  | LetRec of induction_kind * (capture_variable * term * int) list * term
      (* (name, body, decreasing argument) list, where *)
  | Ident of string * subst list option
      (* literal, substitutions.
      * Some [] -> user has given an empty explicit substitution list 
      * None -> user has given no explicit substitution list *)
  | Implicit
  | Meta of int * meta_subst list
  | Num of string * int (* literal, instance *)
  | Sort of sort_kind
  | Symbol of string * int  (* canonical name, instance *)

and capture_variable = Cic.name * term option (* name, type *)
and meta_subst = term option
and subst = string * term
and case_pattern = string * capture_variable list