presol_dualinfer.h

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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/*                                                                           */
/*                  This file is part of the program and library             */
/*         SCIP --- Solving Constraint Integer Programs                      */
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/*    Copyright (C) 2002-2019 Konrad-Zuse-Zentrum                            */
/*                            fuer Informationstechnik Berlin                */
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/*  SCIP is distributed under the terms of the ZIB Academic License.         */
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/*  along with SCIP; see the file COPYING. If not visit scip.zib.de.         */
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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/**@file   presol_dualinfer.h
 * @ingroup PRESOLVERS
 * @brief  dual inference presolver
 * @author Dieter Weninger
 *
 * This presolver exploits dual information for primal variable fixings:
 * 1. The first method is an enhanced dual fixing technique.
 * 2. The second method does dual bound strengthening on continuous primal
 *    variables and applies complementary slackness \f$(A^T y - c)_i > 0 \Rightarrow x_i = 0\f$
 *    for fixing primal variables at their lower bound.
 *
 */

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#ifndef __SCIP_PRESOL_DUALINFER_H__
#define __SCIP_PRESOL_DUALINFER_H__

#include "scip/def.h"
#include "scip/type_retcode.h"
#include "scip/type_scip.h"

#ifdef __cplusplus
extern "C" {
#endif

/** creates the dual inference presolver and includes it in SCIP
 *
 * @ingroup PresolverIncludes
 */
SCIP_EXPORT
SCIP_RETCODE SCIPincludePresolDualinfer(
   SCIP*                 scip                /**< SCIP data structure */
   );

#ifdef __cplusplus
}
#endif

#endif