(* Copyright (C) 2002, 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/.
 *)

val id_tac : ProofEngineTypes.tactic
val fail_tac: ProofEngineTypes.tactic

(* module type Status =
 sig
|+    type external_input_status +|
   type input_status
   type output_status
|+    type external_output_status +|

|+    val internalize: external_input_status -> input_status
   val externalize: output_status -> external_output_status +|

   type tactic

   val mk_tactic : (input_status -> output_status) -> tactic
   val apply_tactic : tactic -> input_status -> output_status

   val id_tac : tactic

   val goals : output_status -> ProofEngineTypes.goal list
   val get_stack : input_status -> stack
   val set_stack : stack -> output_status -> output_status

   val inject : input_status -> output_status
   val focus : goal -> output_status -> input_status
 end *)

module type T =
sig
  type tactic

  val first: tactics: (string * tactic) list -> tactic
  val thens: start: tactic -> continuations: tactic list -> tactic
  val then_: start: tactic -> continuation: tactic -> tactic
  val seq: tactics: tactic list -> tactic (** "folding" of then_ *)
  val repeat_tactic: tactic: tactic -> tactic
  val do_tactic: n: int -> tactic: tactic -> tactic 
  val try_tactic: tactic: tactic -> tactic 
  val solve_tactics: tactics: (string * tactic) list -> tactic

(*   module C:
  sig *)
  val tactic: tactic -> tactic  (** apply tactic to all goal in env *)
  val skip: tactic
  val dot: tactic
  val semicolon: tactic
  val branch: tactic
  val shift: tactic
  val pos: int -> tactic
  val merge: tactic
  val focus: int list -> tactic
  val unfocus: tactic
(*   end *)
end

module Make (S: Continuationals.Status) : T with type tactic = S.tactic

include T with type tactic = ProofEngineTypes.tactic

(* TODO temporary *)
val goals_diff:
  before:ProofEngineTypes.goal list ->
  after:ProofEngineTypes.goal list ->
  opened:ProofEngineTypes.goal list ->
    ProofEngineTypes.goal list * ProofEngineTypes.goal list