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: q_2 -> p. ~q_2. q_2 -> p. p -> q_2.
~p can be inferred via the modus tollens rule. q_2 <-> p can be inferred via the biconditional introduction rule. q_2 <-> p can be inferred via the biconditional introduction rule. p <-> q_2 can be inferred via the biconditional introduction rule. p <-> q_2 can be inferred via the biconditional introduction rule.