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_13: R(x_13) <-> P(x_13). forall x_13: T(x_13). exists x_13: P(x_13).
exists x_13: P(x_13) and T(x_13) can be inferred via the existential conjunction rule. exists x_13: T(x_13) and P(x_13) can be inferred via the existential conjunction rule. forall x_13: R(x_13) -> P(x_13) can be inferred via the universal biconditional elimination rule. forall x_13: P(x_13) -> R(x_13) can be inferred via the universal biconditional elimination rule.