[kali_00]

Understanding basic boolean logic isn't just fundamental to programming, it's a particularly easy component that's usually taught very early, for both reasons.

It takes one table to explain XOR and it's the first one on the page. In ASCII:

  a | b | a XOR b
  --+---+---------
  0 | 0 |    0
  0 | 1 |    1
  1 | 0 |    1
  1 | 1 |    0

If a "programmer" seeing that still can't read code using a XOR, I'd fire them.