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: S(y) -> Q(y). forall y: Q(y) -> U_4(y). exists y: U_4(y) -> Q(y). forall y: U_4(y) -> S(y).
forall y: S(y) -> U_4(y) can be inferred via the universal transitivity rule. forall y: Q(y) -> S(y) can be inferred via the universal transitivity rule. forall y: U_4(y) -> Q(y) can be inferred via the universal transitivity rule. exists y: U_4(y) <-> Q(y) can be inferred via the existential biconditional introduction rule. exists y: Q(y) <-> U_4(y) can be inferred via the existential biconditional introduction rule.