never	nor	xor	nand	and	xnor	or	always
0 ? 0 =	0	1	0	1	0	1	0	1
1 ? 0 =	0	0	1	1	0	0	1	1
1 ? 1 =	0	0	0	0	1	1	1	1

// No 0 ? 1 because 1 ? 0 == 0 ? 1