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_13 <-> r. ~r. s_1 -> p_13. q.
~r and q can be inferred via the conjunction rule. q and ~r can be inferred via the conjunction rule. p_13 -> r can be inferred via the biconditional elimination rule. r -> p_13 can be inferred via the biconditional elimination rule. ~p_13 can be inferred via the biconditional elimination rule.