Translate the following inference to logic notation: For all x, x_14 is fast if and only if x_14 will read a book. If Joseph reads a book, then Susan is a police officer. If Susan were a police officer, then Joseph is fast. Therefore if Susan were a police officer, then Joseph is fast.
forall x: P(x) <-> Q(x). Q(a) -> p. p -> P(a). Therefore p -> P(a).