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: U(x) -> R_4(x). forall x: S(x) -> U(x). forall x: P(x) -> U(x). forall x: S(x) or P(x). forall x: U(x) -> S(x).
forall x: S(x) -> R_4(x) can be inferred via the universal transitivity rule. forall x: P(x) -> R_4(x) can be inferred via the universal transitivity rule. forall x: P(x) -> S(x) can be inferred via the universal transitivity rule. forall x: U(x) can be inferred via the universal disjunction elimination rule. forall x: S(x) <-> U(x) can be inferred via the universal biconditional introduction rule. forall x: U(x) <-> S(x) can be inferred via the universal biconditional introduction rule.