1 /* Congruence Java class declaration and implementation.
2    Copyright (C) 2001-2010 Roberto Bagnara <bagnara@cs.unipr.it>
3    Copyright (C) 2010-2016 BUGSENG srl (http://bugseng.com)
4 
5 This file is part of the Parma Polyhedra Library (PPL).
6 
7 The PPL is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by the
9 Free Software Foundation; either version 3 of the License, or (at your
10 option) any later version.
11 
12 The PPL is distributed in the hope that it will be useful, but WITHOUT
13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
15 for more details.
16 
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software Foundation,
19 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111-1307, USA.
20 
21 For the most up-to-date information see the Parma Polyhedra Library
22 site: http://bugseng.com/products/ppl/ . */
23 
24 package parma_polyhedra_library;
25 
26 //! A linear congruence.
27 /*! \ingroup PPL_Java_interface
28   An object of the class Congruence is an object represeting a congruence:
29   - \f$\cg = \sum_{i=0}^{n-1} a_i x_i + b = 0 \pmod{m}\f$
30 
31   where \f$n\f$ is the dimension of the space,
32   \f$a_i\f$ is the integer coefficient of variable \f$x_i\f$,
33   \f$b\f$ is the integer inhomogeneous term and \f$m\f$ is the integer modulus;
34   if \f$m = 0\f$, then \f$\cg\f$ represents the equality congruence
35   \f$\sum_{i=0}^{n-1} a_i x_i + b = 0\f$
36   and, if \f$m \neq 0\f$, then the congruence \f$\cg\f$ is
37   said to be a proper congruence.
38 */
39 public class Congruence {
40 
41     //! The modulus of the congruence.
42     protected Coefficient mod;
43 
44     //! The value of the left hand side of \p this.
45     Linear_Expression lhs;
46 
47     //! The value of the right hand side of \p this.
48     Linear_Expression rhs;
49 
50     /*! \brief
51       Returns the congruence
52       \f$\mathtt{e1} = \mathtt{e2} \pmod{\mathtt{m}}\f$.
53     */
Congruence(Linear_Expression e1, Linear_Expression e2, Coefficient m)54     public Congruence(Linear_Expression e1, Linear_Expression e2,
55                       Coefficient m) {
56         mod = new Coefficient(m);
57         lhs = e1.clone();
58         rhs = e2.clone();
59     }
60 
61     //! Returns the left hand side of \p this.
left_hand_side()62     public Linear_Expression left_hand_side() {
63         return lhs;
64     }
65 
66     //! Returns the right hand side of \p this.
right_hand_side()67     public Linear_Expression right_hand_side() {
68         return rhs;
69     }
70 
71     //! Returns the relation symbol of \p this.
modulus()72     public Coefficient modulus() {
73         return mod;
74     }
75 
76     //! Returns an ascii formatted internal representation of \p this.
ascii_dump()77     public native String ascii_dump();
78 
79     //! Returns a string representation of \p this.
toString()80     public native String toString();
81 
initIDs()82     private static native void initIDs();
83     static {
initIDs()84         initIDs();
85     }
86 }
87