Translate the following inference to logic notation: There is at least one x for which if y_4 plays squash, then y_4 is reading a book. For all x, if y_4 reads a book, then y_4 is playing squash. For all x, if y_4 plays squash, then y_4 is reading a book. Therefore there is at least one x for which if y_4 plays squash, then y_4 is reading a book.
exists x: P(x) -> Q(x). forall x: Q(x) -> P(x). forall x: P(x) -> Q(x). Therefore exists x: P(x) -> Q(x).