digital logic - What would be the output of A = 0100 and B = 0111 with S = 1 in a 4-bit binary adder-subtractor? - Electrical Engineering Stack Exchange
How to make a 4-bit adder in logic.ly
4-bit binary Adder-Subtractor - GeeksforGeeks
Solved] Figure I shows a 4-bit ripple carry adder realized using ful