Translate the following inference to logic notation: Susan is a scientist. For all x, if x_23 were a scientist, then x_23 is making tea. For all x, if x_23 were a mechanic, then x_23 is making tea. For all x, if x_23 makes tea, then x_23 is a mechanic. Therefore there is at least one x for which x_23 is a mechanic.
P(a). forall x: P(x) -> Q(x). forall x: R(x) -> Q(x). forall x: Q(x) -> R(x). Therefore exists x: R(x).