Translate the following inference to logic notation: There is at least one x for which if x_7 were sad, then x_7 is not a mechanic. For all x, x_7 is a mechanic. For all x, x_7 is sad or x_7 will not read a book. Therefore there is at least one x for which x_7 will not read a book.
exists x: P(x) -> ~Q(x). forall x: Q(x). forall x: P(x) or ~R(x). Therefore exists x: ~R(x).