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_6: ~P_5(x_6). forall x_6: U_4(x_6) -> R(x_6). forall x_6: R(x_6) -> U_4(x_6). forall x_6: R(x_6) -> P_5(x_6). forall x_6: P_5(x_6) -> R(x_6).
forall x_6: ~R(x_6) can be inferred via the universal modus tollens rule. forall x_6: U_4(x_6) -> P_5(x_6) can be inferred via the universal transitivity rule. forall x_6: P_5(x_6) -> U_4(x_6) can be inferred via the universal transitivity rule. forall x_6: U_4(x_6) <-> R(x_6) can be inferred via the universal biconditional introduction rule. forall x_6: R(x_6) <-> U_4(x_6) can be inferred via the universal biconditional introduction rule. forall x_6: R(x_6) <-> P_5(x_6) can be inferred via the universal biconditional introduction rule. forall x_6: P_5(x_6) <-> R(x_6) can be inferred via the universal biconditional introduction rule.