Translate the following inference to logic notation: For all x, x_10 is a politician if and only if x_10 is an electrician. There is at least one x for which x_10 will sleep or x_10 is a politician. For all x, x_10 is an electrician if and only if x_10 is a bartender. For all x, x_10 will not sleep or x_10 is a bartender. Therefore there is at least one x for which x_10 is an electrician.
forall x: P(x) <-> Q(x). exists x: R(x) or P(x). forall x: Q(x) <-> S(x). forall x: ~R(x) or S(x). Therefore exists x: Q(x).