(* 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/.
 *)

let reduction_tac ~reduction ~status:(proof,goal) =
 let curi,metasenv,pbo,pty = proof in
 let metano,context,ty = List.find (function (m,_,_) -> m=goal) metasenv in
  let new_ty = reduction context ty in
   let new_metasenv = 
    List.map
    (function
      (n,_,_) when n = metano -> (metano,context,new_ty)
      | _ as t -> t
    ) metasenv
   in
    (curi,new_metasenv,pbo,pty), [metano]
;;

let simpl_tac = reduction_tac ~reduction:ProofEngineReduction.simpl ;;
let reduce_tac = reduction_tac ~reduction:ProofEngineReduction.reduce ;;
let whd_tac = reduction_tac ~reduction:CicReduction.whd ;;