People think programming is cool and fun. I spent 30 minutes pondering the nature of truth while typing this inanity:

iex(15)> true and false

false

iex(16)> not (true and false)

true

iex(17)> true or false

true

iex(18)> not (true or false)

false

iex(19)> not (true or true)

false

iex(20)> not (false or false)

true