1    	/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
2    	/*                                                                           */
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4    	/*         SCIP --- Solving Constraint Integer Programs                      */
5    	/*                                                                           */
6    	/*  Copyright (c) 2002-2023 Zuse Institute Berlin (ZIB)                      */
7    	/*                                                                           */
8    	/*  Licensed under the Apache License, Version 2.0 (the "License");          */
9    	/*  you may not use this file except in compliance with the License.         */
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11   	/*                                                                           */
12   	/*      http://www.apache.org/licenses/LICENSE-2.0                           */
13   	/*                                                                           */
14   	/*  Unless required by applicable law or agreed to in writing, software      */
15   	/*  distributed under the License is distributed on an "AS IS" BASIS,        */
16   	/*  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. */
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18   	/*  limitations under the License.                                           */
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   prop_probing.h
26   	 * @ingroup PROPAGATORS
27   	 * @brief  probing propagator
28   	 * @author Tobias Achterberg
29   	 */
30   	
31   	/*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
32   	
33   	#ifndef __SCIP_PROP_PROBING_H__
34   	#define __SCIP_PROP_PROBING_H__
35   	
36   	#include "scip/def.h"
37   	#include "scip/type_lp.h"
38   	#include "scip/type_retcode.h"
39   	#include "scip/type_scip.h"
40   	#include "scip/type_var.h"
41   	
42   	#ifdef __cplusplus
43   	extern "C" {
44   	#endif
45   	
46   	/** creates the probing propagator and includes it in SCIP
47   	 *
48   	 * @ingroup PropagatorIncludes
49   	 */
50   	SCIP_EXPORT
51   	SCIP_RETCODE SCIPincludePropProbing(
52   	   SCIP*                 scip                /**< SCIP data structure */
53   	   );
54   	
55   	/**@addtogroup PROPAGATORS
56   	  *
57   	  * @{
58   	  */
59   	
60   	/** applies and evaluates probing of a single variable in the given direction and bound */
61   	SCIP_EXPORT
62   	SCIP_RETCODE SCIPapplyProbingVar(
63   	   SCIP*                 scip,               /**< SCIP data structure */
64   	   SCIP_VAR**            vars,               /**< problem variables */
65   	   int                   nvars,              /**< number of problem variables */
66   	   int                   probingpos,         /**< variable number to apply probing on */
67   	   SCIP_BOUNDTYPE        boundtype,          /**< which bound should be changed */
68   	   SCIP_Real             bound,              /**< which bound should be set */
69   	   int                   maxproprounds,      /**< maximal number of propagation rounds (-1: no limit, 0: parameter settings) */
70   	   SCIP_Real*            impllbs,            /**< array to store lower bounds after applying implications and cliques */
71   	   SCIP_Real*            implubs,            /**< array to store upper bounds after applying implications and cliques */
72   	   SCIP_Real*            proplbs,            /**< array to store lower bounds after full propagation */
73   	   SCIP_Real*            propubs,            /**< array to store upper bounds after full propagation */
74   	   SCIP_Bool*            cutoff              /**< pointer to store whether the probing direction is infeasible */
75   	   );
76   	
77   	/** analyses boundchanges resulting from probing on a variable and performs deduced fixations, aggregations, and domain tightenings
78   	 *
79   	 *  Given a variable probingvar with domain [l,u] and bound tightening results from reducing the
80   	 *  domain once to [l,leftub] and once to [rightlb,u], the method computes and applies resulting
81   	 *  variable fixations, aggregations, implications, and bound changes. Variable probingvar does not
82   	 *  need to be binary.  The whole domain of probingvar need to be covered by the left and right
83   	 *  branches, i.e., we assume leftub >= rightlb for continuous variables or floor(leftub) >=
84   	 *  ceil(rightlb)-1 for discrete variables.  Bounds after applying implications and cliques do not
85   	 *  need to be provided, but if they are omitted and probingvar is a binary variable, then already
86   	 *  existing implications may be added.
87   	 */
88   	SCIP_EXPORT
89   	SCIP_RETCODE SCIPanalyzeDeductionsProbing(
90   	   SCIP*                 scip,               /**< SCIP data structure */
91   	   SCIP_VAR*             probingvar,         /**< the probing variable */
92   	   SCIP_Real             leftub,             /**< upper bound of probing variable in left branch */
93   	   SCIP_Real             rightlb,            /**< lower bound of probing variable in right branch */
94   	   int                   nvars,              /**< number of variables which bound changes should be analyzed */
95   	   SCIP_VAR**            vars,               /**< variables which bound changes should be analyzed */
96   	   SCIP_Real*            leftimpllbs,        /**< lower bounds after applying implications and cliques in left branch, or NULL */
97   	   SCIP_Real*            leftimplubs,        /**< upper bounds after applying implications and cliques in left branch, or NULL */
98   	   SCIP_Real*            leftproplbs,        /**< lower bounds after applying domain propagation in left branch */
99   	   SCIP_Real*            leftpropubs,        /**< upper bounds after applying domain propagation in left branch */
100  	   SCIP_Real*            rightimpllbs,       /**< lower bounds after applying implications and cliques in right branch, or NULL */
101  	   SCIP_Real*            rightimplubs,       /**< upper bounds after applying implications and cliques in right branch, or NULL */
102  	   SCIP_Real*            rightproplbs,       /**< lower bounds after applying domain propagation in right branch */
103  	   SCIP_Real*            rightpropubs,       /**< upper bounds after applying domain propagation in right branch */
104  	   int*                  nfixedvars,         /**< pointer to counter which is increased by the number of deduced variable fixations */
105  	   int*                  naggrvars,          /**< pointer to counter which is increased by the number of deduced variable aggregations */
106  	   int*                  nimplications,      /**< pointer to counter which is increased by the number of deduced implications */
107  	   int*                  nchgbds,            /**< pointer to counter which is increased by the number of deduced bound tightenings */
108  	   SCIP_Bool*            cutoff              /**< buffer to store whether a cutoff is detected */
109  	   );
110  	
111  	/** @} */
112  	
113  	#ifdef __cplusplus
114  	}
115  	#endif
116  	
117  	#endif
118