3 * Interface to relations between expressions. */
6 * GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 #ifndef __GINAC_RELATIONAL_H__
24 #define __GINAC_RELATIONAL_H__
31 /** This class holds a relation consisting of two expressions and a logical
32 * relation between them. */
33 class relational : public basic
35 GINAC_DECLARE_REGISTERED_CLASS(relational, basic)
50 relational(const ex & lhs, const ex & rhs, operators oper=equal);
52 // functions overriding virtual functions from base classes
54 void print(const print_context & c, unsigned level = 0) const;
55 unsigned precedence(void) const {return 20;}
56 bool info(unsigned inf) const;
57 unsigned nops() const;
59 ex eval(int level=0) const;
60 ex simplify_ncmul(const exvector & v) const;
63 bool match_same_type(const basic & other) const;
64 unsigned return_type(void) const;
65 unsigned return_type_tinfo(void) const;
67 // new virtual functions which can be overridden by derived classes
69 virtual ex lhs(void) const;
70 virtual ex rhs(void) const;
72 // non-virtual functions in this class
74 operator bool(void) const;
86 /** Return the relational object handled by an ex. Deprecated: use ex_to<relational>().
87 * This is unsafe: you need to check the type first. */
88 inline const relational &ex_to_relational(const ex &e)
90 return static_cast<const relational &>(*e.bp);
93 /** Specialization of is_exactly_a<relational>(obj) for relational objects. */
94 template<> inline bool is_exactly_a<relational>(const basic & obj)
96 return obj.tinfo()==TINFO_relational;
101 #endif // ndef __GINAC_RELATIONAL_H__