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_5: W_4(x_5) or T(x_5). forall x_5: T(x_5) -> P_5(x_5). forall x_5: P_5(x_5) -> T(x_5). exists x_5: W_4(x_5) -> P_5(x_5).
exists x_5: W_4(x_5) -> T(x_5) can be inferred via the existential transitivity rule. exists x_5: P_5(x_5) can be inferred via the existential disjunction elimination rule. forall x_5: T(x_5) <-> P_5(x_5) can be inferred via the universal biconditional introduction rule. forall x_5: P_5(x_5) <-> T(x_5) can be inferred via the universal biconditional introduction rule.