Translate the following inference to logic notation: There is at least one x for which x_14 is a sailor if and only if x_14 is a mechanic. For all x, x_14 is a mechanic or x_14 is not a scientist. For all x, if x_14 were a sailor, then x_14 is a scientist. Therefore there is at least one x for which x_14 is a scientist if and only if x_14 is a mechanic.
exists x: P(x) <-> Q(x). forall x: Q(x) or ~R(x). forall x: P(x) -> R(x). Therefore exists x: R(x) <-> Q(x).