Translate the following inference to logic notation: For all x, if z were fast, then z is a scientist. Jessica is a scientist if and only if Joseph is a mechanic. For all x, if z were a scientist, then z is fast. Joseph is not a mechanic. Therefore Jessica is not fast.
forall x: P(x) -> Q(x). Q(a) <-> p. forall x: Q(x) -> P(x). ~p. Therefore ~P(a).