Consider the following premises. p_26. q_1 -> q. p_26 <-> p. p_8 -> ~p. ~p_8 -> q_1. Can we infer ~q from them?
 From p_26 <-> p we can infer p_26 -> p. From p_26 -> p, p_26 we can infer p. From p_8 -> ~p, p we can infer ~p_8. From ~p_8 -> q_1, q_1 -> q we can infer ~p_8 -> q. Finally, from ~p_8 -> q, ~p_8 we can infer q, which contradicts ~q. Therefore, the answer is no.