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_7: U(x_7) -> P_5(x_7). forall x_7: P_7(x_7) or U(x_7). forall x_7: ~P_5(x_7). forall x_7: P_5(x_7) -> U(x_7). forall x_7: ~P_7(x_7) or P(x_7).
forall x_7: ~U(x_7) can be inferred via the universal modus tollens rule. forall x_7: U(x_7) or P(x_7) can be inferred via the universal resolution rule. forall x_7: U(x_7) <-> P_5(x_7) can be inferred via the universal biconditional introduction rule. forall x_7: P_5(x_7) <-> U(x_7) can be inferred via the universal biconditional introduction rule.