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4    	/*         SCIP --- Solving Constraint Integer Programs                      */
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24   	
25   	/**@file   cons_symresack.h
26   	 * @ingroup CONSHDLRS
27   	 * @brief  constraint handler for symresack constraints
28   	 * @author Christopher Hojny
29   	 *
30   	 */
31   	
32   	/*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
33   	
34   	#ifndef __SCIP_CONS_SYMRESACK_H__
35   	#define __SCIP_CONS_SYMRESACK_H__
36   	
37   	#include "scip/def.h"
38   	#include "scip/type_cons.h"
39   	#include "scip/type_retcode.h"
40   	#include "scip/type_scip.h"
41   	#include "scip/type_var.h"
42   	
43   	#ifdef __cplusplus
44   	extern "C" {
45   	#endif
46   	
47   	
48   	
49   	/** creates the handler for symresack constraints and includes it in SCIP
50   	 *
51   	 * @ingroup ConshdlrIncludes
52   	 */
53   	SCIP_EXPORT
54   	SCIP_RETCODE SCIPincludeConshdlrSymresack(
55   	   SCIP*                 scip                /**< SCIP data structure */
56   	   );
57   	
58   	/**@addtogroup CONSHDLRS
59   	 *
60   	 * @{
61   	 *
62   	 * @name Symresack Constraints
63   	 *
64   	 * @{
65   	 *
66   	 * Given a permutation that acts on the order of the variables of a (mixed) 0/1-program
67   	 * such that the permutation is a symmetry of the program, this constraint handler can
68   	 * be used to handle the symmetries corresponding to the permutation. The symmetries
69   	 * are handled by enforcing that a binary solution is lexicographically not smaller than
70   	 * its permutation. In a presolving step, we check whether the permutation acts only on
71   	 * binary points. Otherwise, we eliminate the non-binary variables from the permutation.
72   	 * Furthermore, we delete fixed points from the permutation.
73   	 *
74   	 * Moreover, the constraint handler checks whether each cycle of the permutation is
75   	 * contained in a set packing or partitioning constraint. In this case, the symresack
76   	 * is strengthened to a ppsymresack and strong symmetry handling inequalities are added during
77   	 * the initialization of the constraint handler.
78   	 *
79   	 * @pre The permutation is encoded by an array perm for which perm[i] = j if and only if
80   	 * the image of i under the  permutation is j.
81   	 *
82   	 * @pre The permutation given to the constraint handler has to be a symmetry of the
83   	 * underlying problem. This is NOT checked by the constraint handler.
84   	 */
85   	
86   	/** creates a symmetry breaking constraint
87   	 *
88   	 * Depending on the given permutation, either an orbisack or symresack constraint
89   	 * is created.
90   	 */
91   	SCIP_EXPORT
92   	SCIP_RETCODE SCIPcreateSymbreakCons(
93   	   SCIP*                 scip,               /**< SCIP data structure */
94   	   SCIP_CONS**           cons,               /**< pointer to hold the created constraint */
95   	   const char*           name,               /**< name of constraint */
96   	   int*                  perm,               /**< permutation */
97   	   SCIP_VAR**            vars,               /**< variables */
98   	   int                   nvars,              /**< number of variables in vars array */
99   	   SCIP_Bool             ismodelcons,        /**< whether the added constraint is a model constraint */
100  	   SCIP_Bool             initial,            /**< should the LP relaxation of constraint be in the initial LP?
101  	                                              *   Usually set to TRUE. Set to FALSE for 'lazy constraints'. */
102  	   SCIP_Bool             separate,           /**< should the constraint be separated during LP processing?
103  	                                              *   Usually set to TRUE. */
104  	   SCIP_Bool             enforce,            /**< should the constraint be enforced during node processing?
105  	                                              *   TRUE for model constraints, FALSE for additional, redundant constraints. */
106  	   SCIP_Bool             check,              /**< should the constraint be checked for feasibility?
107  	                                              *   TRUE for model constraints, FALSE for additional, redundant constraints. */
108  	   SCIP_Bool             propagate,          /**< should the constraint be propagated during node processing?
109  	                                              *   Usually set to TRUE. */
110  	   SCIP_Bool             local,              /**< is constraint only valid locally?
111  	                                              *   Usually set to FALSE. Has to be set to TRUE, e.g., for branching constraints. */
112  	   SCIP_Bool             modifiable,         /**< is constraint modifiable (subject to column generation)?
113  	                                              *   Usually set to FALSE. In column generation applications, set to TRUE if pricing
114  	                                              *   adds coefficients to this constraint. */
115  	   SCIP_Bool             dynamic,            /**< is constraint subject to aging?
116  	                                              *   Usually set to FALSE. Set to TRUE for own cuts which
117  	                                              *   are separated as constraints. */
118  	   SCIP_Bool             removable,          /**< should the relaxation be removed from the LP due to aging or cleanup?
119  	                                              *   Usually set to FALSE. Set to TRUE for 'lazy constraints' and 'user cuts'. */
120  	   SCIP_Bool             stickingatnode      /**< should the constraint always be kept at the node where it was added, even
121  	                                              *   if it may be moved to a more global node?
122  	                                              *   Usually set to FALSE. Set to TRUE to for constraints that represent node data. */
123  	   );
124  	
125  	
126  	/** creates and captures a symresack constraint
127  	 *
128  	 *  @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons()
129  	 */
130  	SCIP_EXPORT
131  	SCIP_RETCODE SCIPcreateConsSymresack(
132  	   SCIP*                 scip,               /**< SCIP data structure */
133  	   SCIP_CONS**           cons,               /**< pointer to hold the created constraint */
134  	   const char*           name,               /**< name of constraint */
135  	   int*                  perm,               /**< permutation */
136  	   SCIP_VAR**            vars,               /**< variables */
137  	   int                   nvars,              /**< number of variables in vars array */
138  	   SCIP_Bool             ismodelcons,        /**< whether the symresack is a model constraint */
139  	   SCIP_Bool             initial,            /**< should the LP relaxation of constraint be in the initial LP?
140  	                                              *   Usually set to TRUE. Set to FALSE for 'lazy constraints'. */
141  	   SCIP_Bool             separate,           /**< should the constraint be separated during LP processing?
142  	                                              *   Usually set to TRUE. */
143  	   SCIP_Bool             enforce,            /**< should the constraint be enforced during node processing?
144  	                                              *   TRUE for model constraints, FALSE for additional, redundant constraints. */
145  	   SCIP_Bool             check,              /**< should the constraint be checked for feasibility?
146  	                                              *   TRUE for model constraints, FALSE for additional, redundant constraints. */
147  	   SCIP_Bool             propagate,          /**< should the constraint be propagated during node processing?
148  	                                              *   Usually set to TRUE. */
149  	   SCIP_Bool             local,              /**< is constraint only valid locally?
150  	                                              *   Usually set to FALSE. Has to be set to TRUE, e.g., for branching constraints. */
151  	   SCIP_Bool             modifiable,         /**< is constraint modifiable (subject to column generation)?
152  	                                              *   Usually set to FALSE. In column generation applications, set to TRUE if pricing
153  	                                              *   adds coefficients to this constraint. */
154  	   SCIP_Bool             dynamic,            /**< is constraint subject to aging?
155  	                                              *   Usually set to FALSE. Set to TRUE for own cuts which
156  	                                              *   are separated as constraints. */
157  	   SCIP_Bool             removable,          /**< should the relaxation be removed from the LP due to aging or cleanup?
158  	                                              *   Usually set to FALSE. Set to TRUE for 'lazy constraints' and 'user cuts'. */
159  	   SCIP_Bool             stickingatnode      /**< should the constraint always be kept at the node where it was added, even
160  	                                              *   if it may be moved to a more global node?
161  	                                              *   Usually set to FALSE. Set to TRUE to for constraints that represent node data. */
162  	   );
163  	
164  	/** creates and captures a symresack constraint
165  	 *  in its most basic variant, i.e., with all constraint flags set to their default values, which can be set
166  	 *  afterwards using SCIPsetConsFLAGNAME() in scip.h
167  	 *
168  	 *  @see SCIPcreateConsSymresack() for the default constraint flag configuration
169  	 *
170  	 *  @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons()
171  	 */
172  	SCIP_EXPORT
173  	SCIP_RETCODE SCIPcreateConsBasicSymresack(
174  	   SCIP*                 scip,               /**< SCIP data structure */
175  	   SCIP_CONS**           cons,               /**< pointer to hold the created constraint */
176  	   const char*           name,               /**< name of constraint */
177  	   int*                  perm,               /**< permutation */
178  	   SCIP_VAR**            vars,               /**< variables */
179  	   int                   nvars,              /**< number of variables in vars array */
180  	   SCIP_Bool             ismodelcons         /**< whether the symresack is a model constraint */
181  	   );
182  	
183  	/** @} */
184  	
185  	/** @} */
186  	
187  	#ifdef __cplusplus
188  	}
189  	#endif
190  	
191  	#endif
192