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: ~r_1 -> w. ~p_13. p_13 <-> r_1.
p_13 -> r_1 can be inferred via the biconditional elimination rule. r_1 -> p_13 can be inferred via the biconditional elimination rule. ~r_1 can be inferred via the biconditional elimination rule.