What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: ~s. p. u_1 -> w_1. w_1 -> s.
~w_1 can be inferred via the modus tollens rule. u_1 -> s can be inferred via the transitivity rule. ~s and p can be inferred via the conjunction rule. p and ~s can be inferred via the conjunction rule.