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 y: R(y) -> P_3(y). forall y: R(y) <-> S(y). forall y: U_4(y) <-> P_3(y). forall y: ~U_4(y).
forall y: R(y) -> S(y) can be inferred via the universal biconditional elimination rule. forall y: U_4(y) -> P_3(y) can be inferred via the universal biconditional elimination rule. forall y: S(y) -> R(y) can be inferred via the universal biconditional elimination rule. forall y: P_3(y) -> U_4(y) can be inferred via the universal biconditional elimination rule. forall y: ~P_3(y) can be inferred via the universal biconditional elimination rule.