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24   	
25   	/**@file   expr_pow.h
26   	 * @ingroup EXPRHDLRS
27   	 * @brief  power and signed power expression handlers
28   	 * @author Benjamin Mueller
29   	 */
30   	
31   	/*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
32   	
33   	#ifndef __SCIP_EXPR_POW_H__
34   	#define __SCIP_EXPR_POW_H__
35   	
36   	#include "scip/scip.h"
37   	#include "scip/type_expr.h"
38   	
39   	#ifdef __cplusplus
40   	extern "C" {
41   	#endif
42   	
43   	/**@addtogroup EXPRHDLRS
44   	 *
45   	 * @{
46   	 *
47   	 * @name Power and signed power expression
48   	 *
49   	 * These expression handlers provide the power function, that is,
50   	 * \f[
51   	 *   x \mapsto \begin{cases}
52   	 *     x^e & \textrm{if}\; x \geq 0\; \textrm{or}\; e\in\mathbb{Z}, \\
53   	 *     \textrm{undefined}, & \textrm{otherwise}.
54   	 *     \end{cases}
55   	 * \f]
56   	 * and the signed power function, that is,
57   	 * \f[
58   	 *   x \mapsto \textrm{sign}(x) |x|^e
59   	 * \f]
60   	 * for some exponent \f$e\f$.
61   	 *
62   	 * @{
63   	 */
64   	
65   	/** creates a power expression */
66   	SCIP_EXPORT
67   	SCIP_RETCODE SCIPcreateExprPow(
68   	   SCIP*                 scip,               /**< SCIP data structure */
69   	   SCIP_EXPR**           expr,               /**< pointer where to store expression */
70   	   SCIP_EXPR*            child,              /**< single child */
71   	   SCIP_Real             exponent,           /**< exponent of the power expression */
72   	   SCIP_DECL_EXPR_OWNERCREATE((*ownercreate)), /**< function to call to create ownerdata */
73   	   void*                 ownercreatedata     /**< data to pass to ownercreate */
74   	   );
75   	
76   	/** creates a signpower expression */
77   	SCIP_EXPORT
78   	SCIP_RETCODE SCIPcreateExprSignpower(
79   	   SCIP*                 scip,               /**< SCIP data structure */
80   	   SCIP_EXPR**           expr,               /**< pointer where to store expression */
81   	   SCIP_EXPR*            child,              /**< single child */
82   	   SCIP_Real             exponent,           /**< exponent of the power expression */
83   	   SCIP_DECL_EXPR_OWNERCREATE((*ownercreate)), /**< function to call to create ownerdata */
84   	   void*                 ownercreatedata     /**< data to pass to ownercreate */
85   	   );
86   	
87   	/** indicates whether expression is of signpower-type */
88   	SCIP_EXPORT
89   	SCIP_Bool SCIPisExprSignpower(
90   	   SCIP*                 scip,               /**< SCIP data structure */
91   	   SCIP_EXPR*            expr                /**< expression */
92   	   );
93   	
94   	/** @}
95   	  * @}
96   	  */
97   	
98   	/** creates the handler for power expression and includes it into SCIP
99   	 *
100  	 * @ingroup ExprhdlrIncludes
101  	 */
102  	SCIP_EXPORT
103  	SCIP_RETCODE SCIPincludeExprhdlrPow(
104  	   SCIP*                 scip                /**< SCIP data structure */
105  	   );
106  	
107  	/** creates the handler for signed power expression and includes it into SCIP
108  	 *
109  	 * @ingroup ExprhdlrIncludes
110  	 */
111  	SCIP_EXPORT
112  	SCIP_RETCODE SCIPincludeExprhdlrSignpower(
113  	   SCIP*                 scip                /**< SCIP data structure */
114  	   );
115  	
116  	/** computes coefficients of linearization of a square term in a reference point */
117  	SCIP_EXPORT
118  	void SCIPaddSquareLinearization(
119  	   SCIP*                 scip,               /**< SCIP data structure */
120  	   SCIP_Real             sqrcoef,            /**< coefficient of square term */
121  	   SCIP_Real             refpoint,           /**< point where to linearize */
122  	   SCIP_Bool             isint,              /**< whether corresponding variable is a discrete variable, and thus linearization could be moved */
123  	   SCIP_Real*            lincoef,            /**< buffer to add coefficient of linearization */
124  	   SCIP_Real*            linconstant,        /**< buffer to add constant of linearization */
125  	   SCIP_Bool*            success             /**< buffer to set to FALSE if linearization has failed due to large numbers */
126  	   );
127  	
128  	/** computes coefficients of secant of a square term */
129  	SCIP_EXPORT
130  	void SCIPaddSquareSecant(
131  	   SCIP*                 scip,               /**< SCIP data structure */
132  	   SCIP_Real             sqrcoef,            /**< coefficient of square term */
133  	   SCIP_Real             lb,                 /**< lower bound on variable */
134  	   SCIP_Real             ub,                 /**< upper bound on variable */
135  	   SCIP_Real*            lincoef,            /**< buffer to add coefficient of secant */
136  	   SCIP_Real*            linconstant,        /**< buffer to add constant of secant */
137  	   SCIP_Bool*            success             /**< buffer to set to FALSE if secant has failed due to large numbers or unboundedness */
138  	   );
139  	
140  	/** Separation for roots with exponent in [0,1] */
141  	SCIP_EXPORT
142  	void SCIPestimateRoot(
143  	   SCIP*                 scip,               /**< SCIP data structure */
144  	   SCIP_Real             exponent,           /**< exponent */
145  	   SCIP_Bool             overestimate,       /**< should the power be overestimated? */
146  	   SCIP_Real             xlb,                /**< lower bound on x */
147  	   SCIP_Real             xub,                /**< upper bound on x */
148  	   SCIP_Real             xref,               /**< reference point (where to linearize) */
149  	   SCIP_Real*            constant,           /**< buffer to store constant term of estimator */
150  	   SCIP_Real*            slope,              /**< buffer to store slope of estimator */
151  	   SCIP_Bool*            islocal,            /**< buffer to store whether estimator only locally valid, that is,
152  	                                                  it depends on given bounds */
153  	   SCIP_Bool*            success             /**< buffer to store whether estimator could be computed */
154  	   );
155  	
156  	#ifdef __cplusplus
157  	}
158  	#endif
159  	
160  	#endif /* __SCIP_EXPR_POW_H__ */
161