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_4 <-> p_2. ~p_4.
p_4 -> p_2 can be inferred via the biconditional elimination rule. p_2 -> p_4 can be inferred via the biconditional elimination rule. ~p_2 can be inferred via the biconditional elimination rule.