Translate the following inference to logic notation: There is at least one x for which x_10 is a cashier if and only if x_10 is an electrician. For all x, x_10 is an electrician if and only if x_10 is a cashier. Therefore there is at least one x for which if x_10 were a cashier, then x_10 is an electrician.
exists x: P(x) <-> Q(x). forall x: Q(x) <-> P(x). Therefore exists x: P(x) -> Q(x).