Translate the following inference to logic notation: For all x, if x_10 were a police officer, then x_10 is fast. If Robert goes running, then David is a sailor. If John were fast, then Robert is running. Therefore if John were a police officer, then David is a sailor.
forall x: P(x) -> Q(x). p -> q. Q(a) -> p. Therefore P(a) -> q.