1    	/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
2    	/*                                                                           */
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4    	/*         SCIP --- Solving Constraint Integer Programs                      */
5    	/*                                                                           */
6    	/*  Copyright (c) 2002-2023 Zuse Institute Berlin (ZIB)                      */
7    	/*                                                                           */
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11   	/*                                                                           */
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13   	/*                                                                           */
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19   	/*                                                                           */
20   	/*  You should have received a copy of the Apache-2.0 license                */
21   	/*  along with SCIP; see the file LICENSE. If not visit scipopt.org.         */
22   	/*                                                                           */
23   	/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
24   	
25   	/**@file   type_prop.h
26   	 * @ingroup TYPEDEFINITIONS
27   	 * @brief  type definitions for propagators
28   	 * @author Tobias Achterberg
29   	 */
30   	
31   	/** @defgroup DEFPLUGINS_PROP Default Propagators
32   	 *  @ingroup DEFPLUGINS
33   	 *  @brief implementation files (.c files) of the default propagators of SCIP
34   	 */
35   	
36   	/*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
37   	
38   	#ifndef __SCIP_TYPE_PROP_H__
39   	#define __SCIP_TYPE_PROP_H__
40   	
41   	#include "scip/def.h"
42   	#include "scip/type_retcode.h"
43   	#include "scip/type_result.h"
44   	#include "scip/type_scip.h"
45   	#include "scip/type_timing.h"
46   	
47   	#ifdef __cplusplus
48   	extern "C" {
49   	#endif
50   	
51   	typedef struct SCIP_Prop SCIP_PROP;               /**< propagator */
52   	typedef struct SCIP_PropData SCIP_PROPDATA;       /**< locally defined propagator data */
53   	
54   	
55   	/** copy method for propagator plugins (called when SCIP copies plugins)
56   	 *
57   	 *  input:
58   	 *  - scip            : SCIP main data structure
59   	 *  - prop            : the propagator itself
60   	 */
61   	#define SCIP_DECL_PROPCOPY(x) SCIP_RETCODE x (SCIP* scip, SCIP_PROP* prop)
62   	
63   	/** destructor of propagator to free user data (called when SCIP is exiting)
64   	 *
65   	 *  input:
66   	 *  - scip            : SCIP main data structure
67   	 *  - prop            : the propagator itself
68   	 */
69   	#define SCIP_DECL_PROPFREE(x) SCIP_RETCODE x (SCIP* scip, SCIP_PROP* prop)
70   	
71   	/** initialization method of propagator (called after problem was transformed)
72   	 *
73   	 *  input:
74   	 *  - scip            : SCIP main data structure
75   	 *  - prop            : the propagator itself
76   	 */
77   	#define SCIP_DECL_PROPINIT(x) SCIP_RETCODE x (SCIP* scip, SCIP_PROP* prop)
78   	
79   	/** deinitialization method of propagator (called before transformed problem is freed)
80   	 *
81   	 *  input:
82   	 *  - scip            : SCIP main data structure
83   	 *  - prop            : the propagator itself
84   	 */
85   	#define SCIP_DECL_PROPEXIT(x) SCIP_RETCODE x (SCIP* scip, SCIP_PROP* prop)
86   	
87   	/** presolving initialization method of propagator (called when presolving is about to begin)
88   	 *
89   	 *  This method is called when the presolving process is about to begin, even if presolving is turned off.  The
90   	 *  propagator may use this call to initialize its presolving data, before the presolving process begins.
91   	 *
92   	 *  Necessary modifications that have to be performed even if presolving is turned off should be done here or in the
93   	 *  presolving deinitialization call (SCIP_DECL_PROPEXITPRE()).
94   	 *
95   	 *  input:
96   	 *  - scip            : SCIP main data structure
97   	 *  - prop            : the propagator itself
98   	 */
99   	#define SCIP_DECL_PROPINITPRE(x) SCIP_RETCODE x (SCIP* scip, SCIP_PROP* prop)
100  	
101  	/** presolving deinitialization method of propagator (called after presolving has been finished)
102  	 *
103  	 *  This method is called after the presolving has been finished, even if presolving is turned off.
104  	 *  The propagator may use this call e.g. to clean up its presolving data.
105  	 *
106  	 *  Besides necessary modifications and clean up, no time consuming operations should be performed, especially if the
107  	 *  problem has already been solved.  Use the method SCIPgetStatus(), which in this case returns SCIP_STATUS_OPTIMAL,
108  	 *  SCIP_STATUS_INFEASIBLE, SCIP_STATUS_UNBOUNDED, or SCIP_STATUS_INFORUNBD.
109  	 *
110  	 *  input:
111  	 *  - scip            : SCIP main data structure
112  	 *  - prop            : the propagator itself
113  	 */
114  	#define SCIP_DECL_PROPEXITPRE(x) SCIP_RETCODE x (SCIP* scip, SCIP_PROP* prop)
115  	
116  	/** solving process initialization method of propagator (called when branch and bound process is about to begin)
117  	 *
118  	 *  This method is called when the presolving was finished and the branch and bound process is about to begin.
119  	 *  The propagator may use this call to initialize its branch and bound specific data.
120  	 *
121  	 *  Besides necessary modifications and clean up, no time consuming operations should be performed, especially if the
122  	 *  problem has already been solved.  Use the method SCIPgetStatus(), which in this case returns SCIP_STATUS_OPTIMAL,
123  	 *  SCIP_STATUS_INFEASIBLE, SCIP_STATUS_UNBOUNDED, or SCIP_STATUS_INFORUNBD.
124  	 *
125  	 *  input:
126  	 *  - scip            : SCIP main data structure
127  	 *  - prop            : the propagator itself
128  	 */
129  	#define SCIP_DECL_PROPINITSOL(x) SCIP_RETCODE x (SCIP* scip, SCIP_PROP* prop)
130  	
131  	/** solving process deinitialization method of propagator (called before branch and bound process data is freed)
132  	 *
133  	 *  This method is called before the branch and bound process is freed.
134  	 *  The propagator should use this call to clean up its branch and bound data.
135  	 *
136  	 *  input:
137  	 *  - scip            : SCIP main data structure
138  	 *  - prop            : the propagator itself
139  	 *  - restart         : was this exit solve call triggered by a restart?
140  	 */
141  	#define SCIP_DECL_PROPEXITSOL(x) SCIP_RETCODE x (SCIP* scip, SCIP_PROP* prop, SCIP_Bool restart)
142  	
143  	/** presolving method of propagator
144  	 *
145  	 *  The presolver should go through the variables and constraints and tighten the domains or
146  	 *  constraints. Each tightening should increase the given total numbers of changes.
147  	 *
148  	 *  input:
149  	 *  - scip            : SCIP main data structure
150  	 *  - prop            : the propagator itself
151  	 *  - nrounds         : number of presolving rounds already done
152  	 *  - presoltiming    : current presolving timing
153  	 *  - nnewfixedvars   : number of variables fixed since the last call to the presolving method
154  	 *  - nnewaggrvars    : number of variables aggregated since the last call to the presolving method
155  	 *  - nnewchgvartypes : number of variable type changes since the last call to the presolving method
156  	 *  - nnewchgbds      : number of variable bounds tightened since the last call to the presolving method
157  	 *  - nnewholes       : number of domain holes added since the last call to the presolving method
158  	 *  - nnewdelconss    : number of deleted constraints since the last call to the presolving method
159  	 *  - nnewaddconss    : number of added constraints since the last call to the presolving method
160  	 *  - nnewupgdconss   : number of upgraded constraints since the last call to the presolving method
161  	 *  - nnewchgcoefs    : number of changed coefficients since the last call to the presolving method
162  	 *  - nnewchgsides    : number of changed left or right hand sides since the last call to the presolving method
163  	 *
164  	 *  @note the counters state the changes since the last call including the changes of this presolving method during its
165  	 *        last call
166  	 *
167  	 *  @note if the propagator uses dual information for presolving it is nesassary to check via calling SCIPallowWeakDualReds
168  	 *        or SCIPallowStrongDualReds if dual reductions are allowed.
169  	 *
170  	 *  input/output:
171  	 *  - nfixedvars      : pointer to total number of variables fixed of all presolvers
172  	 *  - naggrvars       : pointer to total number of variables aggregated of all presolvers
173  	 *  - nchgvartypes    : pointer to total number of variable type changes of all presolvers
174  	 *  - nchgbds         : pointer to total number of variable bounds tightened of all presolvers
175  	 *  - naddholes       : pointer to total number of domain holes added of all presolvers
176  	 *  - ndelconss       : pointer to total number of deleted constraints of all presolvers
177  	 *  - naddconss       : pointer to total number of added constraints of all presolvers
178  	 *  - nupgdconss      : pointer to total number of upgraded constraints of all presolvers
179  	 *  - nchgcoefs       : pointer to total number of changed coefficients of all presolvers
180  	 *  - nchgsides       : pointer to total number of changed left/right hand sides of all presolvers
181  	 *
182  	 *  output:
183  	 *  - result          : pointer to store the result of the presolving call
184  	 *
185  	 *  possible return values for *result:
186  	 *  - SCIP_UNBOUNDED  : at least one variable is not bounded by any constraint in obj. direction -> problem is unbounded
187  	 *  - SCIP_CUTOFF     : at least one constraint is infeasible in the variable's bounds -> problem is infeasible
188  	 *  - SCIP_SUCCESS    : the presolving method found a reduction
189  	 *  - SCIP_DIDNOTFIND : the presolving method searched, but did not find a presolving change
190  	 *  - SCIP_DIDNOTRUN  : the presolving method was skipped
191  	 *  - SCIP_DELAYED    : the presolving method was skipped, but should be called again
192  	 */
193  	#define SCIP_DECL_PROPPRESOL(x) SCIP_RETCODE x (SCIP* scip, SCIP_PROP* prop, int nrounds, SCIP_PRESOLTIMING presoltiming,  \
194  	      int nnewfixedvars, int nnewaggrvars, int nnewchgvartypes, int nnewchgbds, int nnewholes, \
195  	      int nnewdelconss, int nnewaddconss, int nnewupgdconss, int nnewchgcoefs, int nnewchgsides, \
196  	      int* nfixedvars, int* naggrvars, int* nchgvartypes, int* nchgbds, int* naddholes, \
197  	      int* ndelconss, int* naddconss, int* nupgdconss, int* nchgcoefs, int* nchgsides, SCIP_RESULT* result)
198  	
199  	/** execution method of propagator
200  	 *
201  	 *  Searches for domain propagations. The method is called in the node processing loop.
202  	 *
203  	 *  input:
204  	 *  - scip            : SCIP main data structure
205  	 *  - prop            : the propagator itself
206  	 *  - proptiming      : current point in the node solving loop
207  	 *  - result          : pointer to store the result of the propagation call
208  	 *
209  	 *  possible return values for *result:
210  	 *  - SCIP_CUTOFF     : the current node is infeasible for the current domains
211  	 *  - SCIP_REDUCEDDOM : at least one domain reduction was found
212  	 *  - SCIP_DIDNOTFIND : the propagator searched, but did not find a domain reduction
213  	 *  - SCIP_DIDNOTRUN  : the propagator was skipped
214  	 *  - SCIP_DELAYED    : the propagator was skipped, but should be called again
215  	 *  - SCIP_DELAYNODE  : the current node should be postponed (return value only valid for BEFORELP propagation)
216  	 */
217  	#define SCIP_DECL_PROPEXEC(x) SCIP_RETCODE x (SCIP* scip, SCIP_PROP* prop,  SCIP_PROPTIMING proptiming, SCIP_RESULT* result)
218  	
219  	
220  	/** propagation conflict resolving method of propagator
221  	 *
222  	 *  This method is called during conflict analysis. If the propagator wants to support conflict analysis,
223  	 *  it should call SCIPinferVarLbProp() or SCIPinferVarUbProp() in domain propagation instead of SCIPchgVarLb() or
224  	 *  SCIPchgVarUb() in order to deduce bound changes on variables.
225  	 *  In the SCIPinferVarLbProp() and SCIPinferVarUbProp() calls, the propagator provides a pointer to itself
226  	 *  and an integer value "inferinfo" that can be arbitrarily chosen.
227  	 *  The propagation conflict resolving method can then be implemented, to provide a "reasons" for the bound
228  	 *  changes, i.e. the bounds of variables at the time of the propagation, that forced the propagator to set the
229  	 *  conflict variable's bound to its current value. It can use the "inferinfo" tag to identify its own propagation
230  	 *  rule and thus identify the "reason" bounds. The bounds that form the reason of the assignment must then be provided
231  	 *  by calls to SCIPaddConflictLb(), SCIPaddConflictUb(), SCIPaddConflictBd(), SCIPaddConflictRelaxedLb(),
232  	 *  SCIPaddConflictRelaxedUb(), SCIPaddConflictRelaxedBd(), and/or SCIPaddConflictBinvar() in the propagation conflict
233  	 *  resolving method.
234  	 *
235  	 *  See the description of the propagation conflict resolving method of constraint handlers for further details.
236  	 *
237  	 *  @note if the propagtor uses dual information it is nesassary to check via calling SCIPallowWeakDualReds and
238  	 *        SCIPallowStrongDualReds if dual reductions and propgation with the current cutoff bound, resp., are allowed.
239  	 *
240  	 *  input:
241  	 *  - scip            : SCIP main data structure
242  	 *  - prop            : the propagator itself
243  	 *  - infervar        : the conflict variable whose bound change has to be resolved
244  	 *  - inferinfo       : the user information passed to the corresponding SCIPinferVarLbProp() or SCIPinferVarUbProp() call
245  	 *  - boundtype       : the type of the changed bound (lower or upper bound)
246  	 *  - bdchgidx        : the index of the bound change, representing the point of time where the change took place
247  	 *  - relaxedbd       : the relaxed bound which is sufficient to be explained
248  	 *
249  	 *  output:
250  	 *  - result          : pointer to store the result of the propagation conflict resolving call
251  	 *
252  	 *  possible return values for *result:
253  	 *  - SCIP_SUCCESS    : the conflicting bound change has been successfully resolved by adding all reason bounds
254  	 *  - SCIP_DIDNOTFIND : the conflicting bound change could not be resolved and has to be put into the conflict set
255  	 *
256  	 *  @note it is sufficient to explain/resolve the relaxed bound
257  	 */
258  	#define SCIP_DECL_PROPRESPROP(x) SCIP_RETCODE x (SCIP* scip, SCIP_PROP* prop, SCIP_VAR* infervar, int inferinfo, \
259  	      SCIP_BOUNDTYPE boundtype, SCIP_BDCHGIDX* bdchgidx, SCIP_Real relaxedbd, SCIP_RESULT* result)
260  	
261  	#ifdef __cplusplus
262  	}
263  	#endif
264  	
265  	#endif
266