Create a limited ALU (Arithmetic Logic Unit) circuit using Logism that implements a Full Adder circuit capable of adding 2-4 bit binary numbers and subtracting 2-4 bit binary numbers. You must also implement the ability to select a bitwise AND operation and a bitwise OR operation. For the ALU, it is acceptable to use the Adder and Subtractor circuits that are listed under the "Arithmetic" folder in Logism.
Your circuit must use a multiplexer that will select between the add, subtract, AND, and OR operations. The multiplexer will select the operations using 2 bits for the selection as follows:
00 - Add
01 - Subtract
10 - AND
11 - OR
Your circuit should look similar to the following diagram with the two binary numbers to be added on the left and a bit selector that will select the operation to be performed. When it is 0, the adder circuit should be selected, and when it is 1, the subtraction circuit should be selected. The output of the computation should be on the right. Your circuit should follow this basic format, but you must design all of the actual circuits to perform addition and subtraction. You must design the actual connections between components. The image below is just to give an idea of where to put the inputs, outputs, and processing that occurs in between.