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 z: Q(z) -> U(z). exists z: U(z) <-> Q(z).
exists z: U(z) -> Q(z) can be inferred via the existential biconditional elimination rule. exists z: Q(z) -> U(z) can be inferred via the existential biconditional elimination rule.