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: forall x_9: W(x_9) -> P_9(x_9). forall x_9: W_3(x_9) -> W(x_9). exists x_9: ~P_9(x_9). forall x_9: P_9(x_9) -> W(x_9).
exists x_9: ~W(x_9) can be inferred via the existential modus tollens rule. forall x_9: W_3(x_9) -> P_9(x_9) can be inferred via the universal transitivity rule. forall x_9: W(x_9) <-> P_9(x_9) can be inferred via the universal biconditional introduction rule. forall x_9: P_9(x_9) <-> W(x_9) can be inferred via the universal biconditional introduction rule.