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_3. p_15 -> p. p_15 <-> p. ~p_15.
r_3 and ~p_15 can be inferred via the conjunction rule. ~p_15 and r_3 can be inferred via the conjunction rule. p_15 -> p can be inferred via the biconditional elimination rule. p -> p_15 can be inferred via the biconditional elimination rule. ~p can be inferred via the biconditional elimination rule.