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: u or ~q_3. u <-> p. q_3 or p.
q_3 -> u can be inferred via the rewriting rule. u -> p can be inferred via the biconditional elimination rule. p -> u can be inferred via the biconditional elimination rule.