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: P_8(x_13) or ~R(x_13). forall x_13: P_13(x_13) <-> R(x_13). exists x_13: R(x_13) -> P_13(x_13). forall x_13: ~P_8(x_13).
forall x_13: R(x_13) -> P_8(x_13) can be inferred via the universal rewriting rule. forall x_13: P_13(x_13) -> R(x_13) can be inferred via the universal biconditional elimination rule. forall x_13: R(x_13) -> P_13(x_13) can be inferred via the universal biconditional elimination rule.