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: R_2(z) <-> U(z). U(a_16) and q_1.
U(a_16) can be inferred via the simplification rule. q_1 can be inferred via the simplification rule. forall z: R_2(z) -> U(z) can be inferred via the universal biconditional elimination rule. forall z: U(z) -> R_2(z) can be inferred via the universal biconditional elimination rule.