(* 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 direction = [ `Left | `Right ]
type reduction_kind = [ `Reduce | `Simpl | `Whd ]
type 'term pattern = Pattern of 'term

  (* when an 'ident option is None, the default is to apply the tactic
  to the current goal *)

type ('term, 'ident) tactic =
  | LocatedTactic of location * ('term, 'ident) tactic

  | Absurd
  | Apply of 'term
  | Assumption
  | Change of 'term * 'term * 'ident option (* what, with what, where *)
  | Change_pattern of 'term pattern * 'term * 'ident option
      (* what, with what, where *)
  | Contradiction
  | Cut of 'term
  | Decompose of 'ident * 'ident list (* where, which principles *)
  | Discriminate of 'ident
  | Elim of 'term * 'term option (* what to elim, which principle to use *)
  | ElimType of 'term
  | Exact of 'term
  | Exists
  | Fold of reduction_kind * 'term
  | Fourier
  | Injection of 'ident
  | Intros of int option * 'ident list
  | Left
  | LetIn of 'term * 'ident
(*   | Named_intros of 'ident list (* joined with Intros above *) *)
  | Reduce of reduction_kind * 'term pattern * 'ident option (* what, where *)
  | Reflexivity
  | Replace of 'term * 'term (* what, with what *)
  | Replace_pattern of 'term pattern * 'term
  | Rewrite of direction * 'term * 'ident option
  | Right
  | Ring
  | Split
  | Symmetry
  | Transitivity of 'term

type 'tactic tactical =
  | LocatedTactical of location * 'tactic tactical

  | Fail
  | Do of int * 'tactic tactical
  | IdTac
  | Repeat of 'tactic tactical
  | Seq of 'tactic tactical list (* sequential composition *)
  | Tactic of 'tactic
  | Then of 'tactic tactical * 'tactic tactical list
  | Tries of 'tactic tactical list
      (* try a sequence of tacticals until one succeeds, fail otherwise *)
  | Try of 'tactic tactical (* try a tactical and mask failures *)