00001 #include "MusimatTutorial.h" 00002 MusimatTutorialSection(B0110) { 00003 Print("*** B.1.10 Relations ***"); 00004 /***************************************************************************** 00005 00006 B.1.10 Relations 00007 00008 Relational operators compare pairs of numeric values. The relational operators are: 00009 00010 Operator Comparison 00011 < less than 00012 > greater than 00013 == equal 00014 != not equal 00015 <= less than or equal 00016 >= greater than or equal. 00017 00018 A relational expression compares two values. If the relationship is False, the value of the 00019 relational expression is 0. If the relationship is True, the value of the relational expression 00020 is 1. 00021 00022 For example, trivially, the expression 2 < 3 is True, because 2 is less than 3. Therefore, 00023 if we evaluate this expression and print the result, the value 1 will be printed. 00024 *****************************************************************************/ 00025 00026 Print("2 < 3 is ", 2 < 3); // will print 1 00027 Print("2 > 3 is ", 2 > 3); // will print 0 00028 00029 /***************************************************************************** 00030 Because "=" has already been given the meaning of assignment, we must choose another way to 00031 express equality, which we do by putting two equals signs together: "==". For example, the expres- 00032 sion x == y is True if x and y have the same value. 00033 00034 Inequality is expressed by !=, so for example, x != y is True if x and y have different values. 00035 *****************************************************************************/ 00036 00037 Integer x = 2; 00038 Integer y = 3; 00039 Print("x == y is ", x == y); // will print 0 00040 Print("x != y is ", x != y); // will print 1 00041 00042 /***************************************************************************** 00043 Musimat defines True == 1 and False == 0. 00044 *****************************************************************************/ 00045 00046 Print("True is ", True); 00047 Print("False is ", False); 00048 00049 /***************************************************************************** 00050 Besides Integer and Real, there is also a data type called Bool that can store 00051 the truth value of a relational expression. 00052 *****************************************************************************/ 00053 00054 Bool t = True; 00055 Bool f = False; 00056 Print("t == True ", t == True); // prints 1 00057 Print("f == False ", f == False); // prints 1 00058 00059 } 00060 00062 /* $Revision: 1.2 $ $Date: 2006/09/05 06:32:25 $ $Author: dgl $ $Name: $ $Id: B0110.cpp,v 1.2 2006/09/05 06:32:25 dgl Exp $ */ 00063 // The Musimat Tutorial � 2006 Gareth Loy 00064 // Derived from Chapter 9 and Appendix B of "Musimathics Vol. 1" � 2006 Gareth Loy 00065 // and published exclusively by The MIT Press. 00066 // This program is released WITHOUT ANY WARRANTY; without even the implied 00067 // warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 00068 // For information on usage and redistribution, and for a DISCLAIMER OF ALL 00069 // WARRANTIES, see the file, "LICENSE.txt," in this distribution. 00070 // "Musimathics" is available here: http://mitpress.mit.edu/catalog/item/default.asp?ttype=2&tid=10916 00071 // Gareth Loy's Musimathics website: http://www.musimathics.com/ 00072 // The Musimat website: http://www.musimat.com/ 00073 // This program is released under the terms of the GNU General Public License 00074 // available here: http://www.gnu.org/licenses/gpl.txt 00075
1.7.2