The clocked circuit in Figure P12.20 is an arbiter. Suppose two devices, 1 and 2, can request a resource such as a bus at any instant. The problem is to ensure that only one requester is granted the resourceeven if both requests are made simultaneously. The circuit of device 2 has two request inputs plus a clock and two grant outputs. Explain how the circuit is able to perform its function reliably. Note that the circuit uses edge-triggered flip-flops and that it is immune to metastability.