Translate the following inference to logic notation: For all x, if x_4 reads a book, then x_4 is a scientist. For all x, x_4 is a janitor. There is at least one x for which if x_4 reads a book, then x_4 is not a janitor. For all x, if x_4 were a scientist, then x_4 is reading a book. Therefore there is at least one x for which x_4 is not a scientist.
forall x: P(x) -> Q(x). forall x: R(x). exists x: P(x) -> ~R(x). forall x: Q(x) -> P(x). Therefore exists x: ~Q(x).