What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: ~R_12(a_12). w_4 <-> s. forall x_12: R_12(x_12) <-> S_12(x_12). w_4 -> S_12(a_12).
w_4 -> s can be inferred via the biconditional elimination rule. s -> w_4 can be inferred via the biconditional elimination rule. forall x_12: R_12(x_12) -> S_12(x_12) can be inferred via the universal biconditional elimination rule. forall x_12: S_12(x_12) -> R_12(x_12) can be inferred via the universal biconditional elimination rule.