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: U(y) -> T_4(y). exists y: U(y) <-> Q_1(y). forall y: T_4(y) -> Q_1(y).
forall y: U(y) -> Q_1(y) can be inferred via the universal transitivity rule. exists y: U(y) -> Q_1(y) can be inferred via the existential biconditional elimination rule. exists y: Q_1(y) -> U(y) can be inferred via the existential biconditional elimination rule.