Consider the following premises. s. q -> w. q -> ~q_13. q_13. w -> q. Can we infer w from them?
 From q -> ~q_13, q_13 we can infer ~q. From q -> w, w -> q we can infer q <-> w. Finally, from q <-> w, ~q we can infer ~w, which contradicts w. Therefore, the answer is no.