What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? R(c) <-> R_21(e). forall z_2: R(z_2) <-> S(z_2). w_3. forall x_21: ~R_21(x_21).
R(c) -> R_21(e). R_21(e) -> R(c). forall z_2: R(z_2) -> S(z_2). forall z_2: S(z_2) -> R(z_2).