12.

(Continued)

In the truth table above, there are two inputs: input A and input B. There are four possible

the binary numbers which equal 0, 1, 2, and 3. Notice, in the truth table above, the input

combinations and the vertical columns are set (from top to bottom) like the binary

numbers 00, 01, 10, and 11. A truth table for three inputs has eight possible input

below.

How many possible combinations of inputs are there for any four-input logic diagram?