Source code in the c programming language

#include <stdio.h>
 
typedef enum {
  TRITTRUE,  /* In this enum, equivalent to integer value 0 */
  TRITMAYBE, /* In this enum, equivalent to integer value 1 */
  TRITFALSE  /* In this enum, equivalent to integer value 2 */
} trit;
 
/* We can trivially find the result of the operation by passing
   the trinary values as indeces into the lookup tables' arrays. */
trit tritNot[3] = {TRITFALSE , TRITMAYBE, TRITTRUE};
trit tritAnd[3][3] = { {TRITTRUE, TRITMAYBE, TRITFALSE},
                       {TRITMAYBE, TRITMAYBE, TRITFALSE},
                       {TRITFALSE, TRITFALSE, TRITFALSE} };
 
trit tritOr[3][3] = { {TRITTRUE, TRITTRUE, TRITTRUE},
                      {TRITTRUE, TRITMAYBE, TRITMAYBE},
                      {TRITTRUE, TRITMAYBE, TRITFALSE} };
 
trit tritThen[3][3] = { { TRITTRUE, TRITMAYBE, TRITFALSE},
                        { TRITTRUE, TRITMAYBE, TRITMAYBE},
                        { TRITTRUE, TRITTRUE, TRITTRUE } };
 
trit tritEquiv[3][3] = { { TRITTRUE, TRITMAYBE, TRITFALSE},
                         { TRITMAYBE, TRITMAYBE, TRITMAYBE},
                         { TRITFALSE, TRITMAYBE, TRITTRUE } };

/* Everything beyond here is just demonstration */

const char* tritString[3] = {"T", "?", "F"};

void demo_binary_op(trit operator[3][3], const char* name)
{
  trit operand1 = TRITTRUE; /* Declare. Initialize for CYA */
  trit operand2 = TRITTRUE; /* Declare. Initialize for CYA */

  /* Blank line */
  printf("\n");

  /* Demo this operator */
  for( operand1 = TRITTRUE; operand1 <= TRITFALSE; ++operand1 )
  {
    for( operand2 = TRITTRUE; operand2 <= TRITFALSE; ++operand2 )
    {
      printf("%s %s %s: %s\n", tritString[operand1],
                               name,
                               tritString[operand2],
                               tritString[operator[operand1][operand2]]);
    }
  }

}

int main()
{
  trit op1 = TRITTRUE; /* Declare. Initialize for CYA */
  trit op2 = TRITTRUE; /* Declare. Initialize for CYA */
 
  /* Demo 'not' */
  for( op1 = TRITTRUE; op1 <= TRITFALSE; ++op1 )
  {
    printf("Not %s: %s\n", tritString[op1], tritString[tritNot[op1]]);
  }
  demo_binary_op(tritAnd, "And");
  demo_binary_op(tritOr, "Or");
  demo_binary_op(tritThen, "Then");
  demo_binary_op(tritEquiv, "Equiv");

 
  return 0;
}


#include <stdio.h>

typedef enum { t_F = -1, t_M, t_T } trit;

trit t_not  (trit a) { return -a; }
trit t_and  (trit a, trit b) { return a < b ? a : b; }
trit t_or   (trit a, trit b) { return a > b ? a : b; }
trit t_eq   (trit a, trit b) { return a * b; }
trit t_imply(trit a, trit b) { return -a > b ? -a : b; }
char t_s(trit a) { return "F?T"[a + 1]; }

#define forall(a) for(a = t_F; a <= t_T; a++)
void show_op(trit (*f)(trit, trit), const char *name) {
	trit a, b;
	printf("\n[%s]\n    F ? T\n  -------", name);
	forall(a) {
		printf("\n%c |", t_s(a));
		forall(b) printf(" %c", t_s(f(a, b)));
	}
	puts("");
}

int main(void)
{
	trit a;

	puts("[Not]");
	forall(a) printf("%c | %c\n", t_s(a), t_s(t_not(a)));

	show_op(t_and,   "And");
	show_op(t_or,    "Or");
	show_op(t_eq,    "Equiv");
	show_op(t_imply, "Imply");

	return 0;
}


#include <stdio.h>
#include <stdlib.h>

typedef double half_truth, maybe;

inline maybe not3(maybe a) { return 1 - a; }

inline maybe
and3(maybe a, maybe b) { return a * b; }

inline maybe
or3(maybe a, maybe b) { return a + b - a * b; }

inline maybe
eq3(maybe a, maybe b) { return 1 - a - b + 2 * a * b; }

inline maybe
imply3(maybe a, maybe b) { return or3(not3(a), b); }

#define true3(x) ((x) * RAND_MAX > rand())
#define if3(x) if (true3(x))

int main()
{
	maybe roses_are_red = 0.25; /* they can be white or black, too */
	maybe violets_are_blue = 1; /* aren't they just */
	int i;

	puts("Verifying flowery truth for 40 times:\n");

	puts("Rose is NOT red:"); /* chance: .75 */
	for (i = 0; i < 40 || !puts("\n"); i++)
		printf( true3( not3(roses_are_red) ) ? "T" : "_");

	/* pick a rose and a violet; */
	puts("Rose is red AND violet is blue:");
	/* chance of rose being red AND violet being blue is .25 */
	for (i = 0; i < 40 || !puts("\n"); i++)
		printf( true3( and3(roses_are_red, violets_are_blue) )
			? "T" : "_");

	/* chance of rose being red OR violet being blue is 1 */
	puts("Rose is red OR violet is blue:");
	for (i = 0; i < 40 || !puts("\n"); i++)
		printf( true3( or3(roses_are_red, violets_are_blue) )
			? "T" : "_");

	/* pick two roses; chance of em being both red or both not red is .625 */
	puts("This rose is as red as that rose:");
	for (i = 0; i < 40 || !puts("\n"); i++)
		if3(eq3(roses_are_red, roses_are_red)) putchar('T');
		else putchar('_');

	return 0;
}