1. The problem statement, all variables and given/known data 2. Relevant equations n/a 3. The attempt at a solution I understand how to read the truth table. I understand that A, B, C, D are the inputs where 10 possible inputs are shown. However, with little to no sources available, I am lost on behalf of how this image came about to finding the outputs for W, X, Y, & Z just from looking at the right hand column from the left image of the braille readings. Can somebody possibly guide me to where the output numbers came from? Thank you!