Translate the following inference to logic notation: For all x, x_12 will work. For all x, if x_12 plays squash, then x_12 is not working. Mary is an electrician if and only if Jennifer is playing squash. Therefore Mary is not an electrician.
forall x: P(x). forall x: Q(x) -> ~P(x). p <-> Q(a). Therefore ~p.