Bool

A Bool is true or false. Comparisons give one, and and, or and not combine them:

3 < 4 and not (1 > 2)

true

and and or are connectives of the language, so the right side is evaluated only when the left side does not decide the answer.

A Bool is not a number, and compares only with another Bool:

true == 1

type error: `Eq` for Bool compares with Bool, not Int
 --> <expression>:1:1
  |
1 | true == 1
  | ^^^^^^^^^

A condition must be a Bool. a given condition otherwise b chooses a value by one:

pages = 412
"long" given pages > 300 otherwise "short"

"long"

A Bool is a Scalar but not Orderable: true < false means nothing.