# Need some clarification on reading this truth table

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1. Oct 31, 2015

### Aristotle

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!

2. Oct 31, 2015

### phinds

Presumably, they are based on the Braille characters. They certainly correspond exactly to them so it seems rather obvious. It's likely just one of those cases where you don't happen to see something and then when you do you have to smack yourself in the forehead.

3. Oct 31, 2015

### Aristotle

Well...you see..that's the problem..I looked up the 3 dots in braille corresponding to A= 0, B = 0, C = 0, D = 0 from the left hand truth table..and in terms of numbers, those 3 dots is equivalent to the number 0. I still don't know how they got W= 0 X= 1, Y = 1, & Z=1 from the right hand truth table.

4. Oct 31, 2015

### phinds

You're overlooking the obvious. They clearly label the two column on the right as W over Z and then X over Y. The presence or absence of dots corresponds exactly, as I said, to the W,X,Y,Z shown.

5. Oct 31, 2015

### Aristotle

Okay you deserve a 'like'....I see it now haha.

6. Oct 31, 2015

### phinds

See, I TOLD you you'd have to smack yourself in the forehead. We all do it from time to time.

7. Oct 31, 2015