What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? w_2 <-> S_12(a_12). forall x_12: W(x_12) <-> S_12(x_12). W(a_12) or w_2.
w_2 -> S_12(a_12). S_12(a_12) -> w_2. forall x_12: W(x_12) -> S_12(x_12). forall x_12: S_12(x_12) -> W(x_12).