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_15: P_15(x_15) <-> T(x_15). forall x_15: T_1(x_15) or W(x_15). forall x_15: W(x_15) -> T(x_15). forall x_15: P_12(x_15) <-> T_1(x_15). forall x_15: P_12(x_15) -> P_15(x_15).
forall x_15: P_15(x_15) -> T(x_15) can be inferred via the universal biconditional elimination rule. forall x_15: P_12(x_15) -> T_1(x_15) can be inferred via the universal biconditional elimination rule. forall x_15: T(x_15) -> P_15(x_15) can be inferred via the universal biconditional elimination rule. forall x_15: T_1(x_15) -> P_12(x_15) can be inferred via the universal biconditional elimination rule.