Consider the following premises. t <-> U(b). ~t. forall x: U(x) <-> W_4(x). Can we infer W_4(b) from them?
 From forall x: U(x) <-> W_4(x) we can infer forall x: W_4(x) -> U(x). From forall x: W_4(x) -> U(x) we can infer W_4(b) -> U(b). From t <-> U(b), ~t we can infer ~U(b). Finally, from W_4(b) -> U(b), ~U(b) we can infer ~W_4(b), which contradicts W_4(b). Therefore, the answer is no.