Finite state machines
	Example:				Start state
	States: represented by circles, 2-bit values q1q0
		N states require ceil(lg N) bits to represent (the ceiling of log base 2 of N)
	Inputs: represented by arrows labeled x (number of bits depends on number of transitions)
		2k arrows for k bits of input
	Trace:		State	00 (Start)		01	10	01	01	10
			Input	1		1	0	0	1