Translate the following inference to logic notation: For all x, x_18 is a server if and only if x_18 is a police officer. For all x, if x_18 were an artist, then x_18 is a server. For all x, if x_18 were fast, then x_18 is a police officer. There is at least one x for which x_18 is fast or x_18 is an artist. For all x, x_18 is a taxi driver. Therefore there is at least one x for which x_18 is a police officer.
forall x: P(x) <-> Q(x). forall x: R(x) -> P(x). forall x: S(x) -> Q(x). exists x: S(x) or R(x). forall x: T(x). Therefore exists x: Q(x).