Consider the following premises. t_2. forall y: ~T_4(y). T_4(a_14) <-> w. Can we infer w from them?
 From forall y: ~T_4(y) we can infer ~T_4(a_14). Finally, from T_4(a_14) <-> w, ~T_4(a_14) we can infer ~w, which contradicts w. Therefore, the answer is no.