Translate the following inference to logic notation: For all x, if x_7 were rich, then x_7 is a mechanic. There is at least one x for which if x_7 were a mechanic, then x_7 is rich. For all x, if x_7 were a mechanic, then x_7 is rich. Therefore there is at least one x for which if x_7 were a mechanic, then x_7 is rich.
forall x: P(x) -> Q(x). exists x: Q(x) -> P(x). forall x: Q(x) -> P(x). Therefore exists x: Q(x) -> P(x).