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: ~p_2 or s. w -> r_16. s -> r_16. s_1 -> ~r_16. u_3 <-> s_1. p_2 or w.
w or s can be inferred via the resolution rule. u_3 -> s_1 can be inferred via the biconditional elimination rule. s_1 -> u_3 can be inferred via the biconditional elimination rule.