Translate the following inference to logic notation: For all x, if x_12 were a cashier, then x_12 is a taxi driver. Patricia is making tea. If Mary were a taxi driver, then Mary is a cashier. If Mary were a taxi driver, then Patricia is not making tea. Therefore Mary is not a cashier.
forall x: P(x) -> Q(x). p. Q(a) -> P(a). Q(a) -> ~p. Therefore ~P(a).