Ch 04

cc/ @fabioyamate @carlosgaldino.

Please review.
considering the `Bool` type, this pattern matching is unnecessary, since any pattern that is not both `False`, will have a `True` in either left or right, so the just the last one is enough to ensure that it will return true.

so in the end this pattern matching is equivalent to the last one `(vvvv)`, so you are still missing one version.