Finite state machines: flip-flop
	T flip-flop:
						q	T	q+	z	D
		State: 1 bit (q)				0	0	0	0	0
		Input: 1 bit (T)				0	1	1	0	1
		Output: current state (z)				1	0	1	1	1
						1	1	0	1	0
	In state 0:						In state 1:
		input 0 gives new state 0 (hold)						input 0 gives new state 1 (hold)
		input 1 gives new state 1 (toggle)						input 1 gives new state 0 (toggle)
	Note that we can implement either type of flip-flop with the other type
		and some combinational circuit