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_6: W(x_6) -> Q_6(x_6). forall x_6: ~Q_6(x_6). exists x_6: W(x_6) <-> R_1(x_6).
forall x_6: ~W(x_6) can be inferred via the universal modus tollens rule. exists x_6: W(x_6) -> R_1(x_6) can be inferred via the existential biconditional elimination rule. exists x_6: R_1(x_6) -> W(x_6) can be inferred via the existential biconditional elimination rule.