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. r_1 or q_4. ~p_12. p_12 <-> r_1.
p and ~p_12 can be inferred via the conjunction rule. ~p_12 and p can be inferred via the conjunction rule. p_12 -> r_1 can be inferred via the biconditional elimination rule. r_1 -> p_12 can be inferred via the biconditional elimination rule. ~r_1 can be inferred via the biconditional elimination rule.