Right Complementation

When given a Truth Table, you see two columns of two different values that are related to each other and show opposite relationships, most of the time they are represented by F for false and T for true. Right Complementation is the opposite of the second column, or the right one. When representing each of the results for a 4 by 2 table, there are 16 possible results, one of them being the right complementation, which is actually represented by negation q.

• Matt Haas
• http://en.wikipedia.org/wiki/Truth_table

equivalence/if and only if

The opposite of an XOR, if something is T and T, then it would be T when applied.

• http://mathworld.wolfram.com/XNOR.html

Demonstration of the indicated keyword.

The following is the code used to demonstrate if and only if/equivalence and the resulting output when the program is run:

  1 #include <stdio.h>
  2 
  3 char logicor( char, char );
  4 
  5 char logiciff( char a, char b )
  6 {
  7     char x;
  8     if(a == b)
  9         x = 1;
 10     else
 11         x = 0;
 12     return(x);
 13 }
 14 
 15 int main()
 16 {
 17     char p = 1;
 18     char q = 1;
 19 
 20 // Printing the OR Truth Table
 21 
 22     printf("\nTreat 0 as false, and 1 as true.\n\tXOR Truth Table:\n\n");
 23     printf("\t P | Q | X \n");
 24     printf("\t___________\n");
 25 
 26 // Printing the first set of values (values for p, q, and the result of p|q)
 27 
 28     printf("\t %d | %d | %d \n", p, q, logiciff( p, q ));
 29     q = 0;
 30     printf("\t %d | %d | %d \n", p, q, logiciff( p, q ));
 31     p = 0;
 32     q = 1;
 33     printf("\t %d | %d | %d \n", p, q, logiciff( p, q ));
 34     q = 0;
 35     printf("\t %d | %d | %d \n\n", p, q, logiciff( p, q ));
 36 
 37 // Printing PART 3
 38 
 39 /*  printf("\tOR Truth Table comparing X and Q:\n\n");
 40     printf("\t P | Q | X | ( X|Q )\n");
 41     printf("\t____________________\n");
 42 
 43     p = 1;
 44     q = 1;
 45 
 46     printf("\t %d | %d | %d |    %d \n", p, q, logicor( p, q ), logicor( logicor( p, q ), q ));
 47     q = 0;
 48     printf("\t %d | %d | %d |    %d \n", p, q, logicor( p, q ), logicor( logicor( p, q ), q ));
 49     p = 0;
 50     q = 1;
 51     printf("\t %d | %d | %d |    %d \n", p, q, logicor( p, q ), logicor( logicor( p, q ), q ));
 52     q = 0;
 53     printf("\t %d | %d | %d |    %d \n", p, q, logicor( p, q ), logicor( logicor( p, q ), q ));*/
 54     return(0);
 55 }

Alternatively (or additionally), if you want to demonstrate something on the command-line, you can do so as follows:

lab46:~/src/opus/opus1$ ./iff

Treat 0 as false, and 1 as true.
	XOR Truth Table:

	 P | Q | X 
	___________
	 1 | 1 | 1 
	 1 | 0 | 0 
	 0 | 1 | 0 
	 0 | 0 | 1 

lab46:~/src/opus/opus1$