(*
This file is part of the dpll(t) engine sammy
Copyright (C) 2004  The University of Iowa
George Hagen

This program 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.

This program 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 this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*)

(* lset.mli *)

(** Container class for holding temporary clauses (lemmas and instances). 

Here "lemma" may refer to either a proper lemma (consequence) or a 
user-defined clause, usually a generated instance of a formula. *)

exception IsetOutOfSpace

(** Container class for holding a number of lemmas, 
initially containing null-clauses. 
The int is to indicate the restart depth of the current search (0 if there is no iterative deepening).
The boolean is to indicate if this is to hold lemmas ([true]) or instances ([false])*)
class iset :
object

  method add_instance : Global.pred_id list list -> unit
  (** Adds a new instance to the list of lemmas.
  Each "instance" consists of one or more clauses derived froma single source
  clause.
  Side effects: may discard bottommost inactive lemma, all newly added 
  instances are considered "most recent lemmas".
  *)

  method clear : unit
  (** clears the lset of all entries *)

  method print : unit
  (** Prints out some statistics about these lemmas. *)

end
