What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? w_1 -> t_1. ~t_1. p_9 <-> s_2. ~p_9.
~w_1. ~t_1 and ~p_9. ~p_9 and ~t_1. p_9 -> s_2. s_2 -> p_9. ~s_2.