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_7. p_7 or ~q_7.
q_7 -> p_7 can be inferred via the rewriting rule. p_4 -> p_7 can be inferred via the biconditional elimination rule. p_7 -> p_4 can be inferred via the biconditional elimination rule.