If a is a symbol and s is a string, define #a(s) to be the number of occurrences of a in s. For example, #1(101100101) = 5. Define #a(s) inductively, and then prove by structural induction that for any strings s and t, #a(s· t) = #a(s) + #a(t).

Once the twisted pair cable is connected and a network is established the led lights at the back of the computer should be steady. on most ethernet adapters nowadays, a steady green light means that the connection is actively connected to a valid partner at the opposite end. if the status of the led starts flashing, this means that there’s some activity and data is being transferred.