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: q_8 -> r_4. w_1 -> q_8. p <-> w_1. ~p. r_4 -> w_1.
q_8 -> w_1 can be inferred via the transitivity rule. w_1 -> r_4 can be inferred via the transitivity rule. r_4 -> q_8 can be inferred via the transitivity rule. p -> w_1 can be inferred via the biconditional elimination rule. w_1 -> p can be inferred via the biconditional elimination rule. ~w_1 can be inferred via the biconditional elimination rule.