Task: Ternary logic
C: #include <stdio.h>
 
typedef enum {
  TRITTRUE,  
  TRITMAYBE, 
  TRITFALSE  
} trit;
 

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 } };



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

void demo_binary_op(trit operator[3][3], const char* name)
{
  trit operand1 = TRITTRUE; 
  trit operand2 = TRITTRUE; 

  
  printf("\n");

  
  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; 
  trit op2 = TRITTRUE; 
 
  
  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;
}

Python: class Trit(int):
    def __new__(cls, value):
        if value == 'TRUE':
            value = 1
        elif value == 'FALSE':
            value = 0
        elif value == 'MAYBE':
            value = -1
        return super(Trit, cls).__new__(cls, value // (abs(value) or 1)) 

    def __repr__(self):
        if self > 0:
            return 'TRUE'
        elif self == 0:
            return 'FALSE'
        return 'MAYBE'

    def __str__(self):
        return repr(self)

    def __bool__(self):
        if self > 0:
            return True
        elif self == 0:
            return False
        else:
            raise ValueError("invalid literal for bool(): '%s'" % self)

    def __or__(self, other):
        if isinstance(other, Trit):
            return _ttable[(self, other)][1]
        else:
            try:
                return _ttable[(self, Trit(bool(other)))][1]
            except:
                return NotImplemented

    def __ror__(self, other):
        if isinstance(other, Trit):
            return _ttable[(self, other)][1]
        else:
            try:
                return _ttable[(self, Trit(bool(other)))][1]
            except:
                return NotImplemented

    def __and__(self, other):
        if isinstance(other, Trit):
            return _ttable[(self, other)][0]
        else:
            try:
                return _ttable[(self, Trit(bool(other)))][0]
            except:
                return NotImplemented

    def __rand__(self, other):
        if isinstance(other, Trit):
            return _ttable[(self, other)][0]
        else:
            try:
                return _ttable[(self, Trit(bool(other)))][0]
            except:
                return NotImplemented

    def __xor__(self, other):
        if isinstance(other, Trit):
            return _ttable[(self, other)][2]
        else:
            try:
                return _ttable[(self, Trit(bool(other)))][2]
            except:
                return NotImplemented

    def __rxor__(self, other):
        if isinstance(other, Trit):
            return _ttable[(self, other)][2]
        else:
            try:
                return _ttable[(self, Trit(bool(other)))][2]
            except:
                return NotImplemented

    def __invert__(self):
        return _ttable[self]
    
    def __getattr__(self, name):
        if name in ('_n', 'flip'):
            
            
            
            return _ttable[self]
        else:
            raise AttributeError 


        
TRUE, FALSE, MAYBE = Trit(1), Trit(0), Trit(-1)

_ttable = {
    
         TRUE: FALSE,
        FALSE:  TRUE,
        MAYBE: MAYBE,
    
        (MAYBE, MAYBE): (MAYBE, MAYBE, MAYBE),
        (MAYBE, FALSE): (FALSE, MAYBE, MAYBE),
        (MAYBE,  TRUE): (MAYBE,  TRUE, MAYBE),
        (FALSE, MAYBE): (FALSE, MAYBE, MAYBE),
        (FALSE, FALSE): (FALSE, FALSE, FALSE),
        (FALSE,  TRUE): (FALSE,  TRUE,  TRUE),
        ( TRUE, MAYBE): (MAYBE,  TRUE, MAYBE),
        ( TRUE, FALSE): (FALSE,  TRUE,  TRUE),
        ( TRUE,  TRUE): ( TRUE,  TRUE, FALSE),
    }


values = ('FALSE', 'TRUE ', 'MAYBE')

print("\nTrit logical inverse, '~'")
for a in values:
    expr = '~%s' % a
    print('  %s = %s' % (expr, eval(expr)))

for op, ophelp in (('&', 'and'), ('|', 'or'), ('^', 'exclusive-or')):
    print("\nTrit logical %s, '%s'" % (ophelp, op))
    for a in values:
        for b in values:
            expr = '%s %s %s' % (a, op, b)
            print('  %s = %s' % (expr, eval(expr)))