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: exists x_9: T(x_9) <-> Q_9(x_9). forall x_9: T(x_9) or P(x_9). forall x_9: Q_9(x_9) -> R_1(x_9). forall x_9: P(x_9) -> R_1(x_9).
exists x_9: T(x_9) -> Q_9(x_9) can be inferred via the existential biconditional elimination rule. exists x_9: Q_9(x_9) -> T(x_9) can be inferred via the existential biconditional elimination rule.