Translate the following inference to logic notation: For all x, x_7 is a lawyer if and only if x_7 is a sailor. For all x, if x_7 goes running, then x_7 is a lawyer. There is at least one x for which if x_7 were a taxi driver, then x_7 is running. Therefore there is at least one x for which if x_7 were a taxi driver, then x_7 is a sailor.
forall x: P(x) <-> Q(x). forall x: R(x) -> P(x). exists x: S(x) -> R(x). Therefore exists x: S(x) -> Q(x).