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. q_3 -> t. u <-> p. t -> p.
q_3 -> p can be inferred via the transitivity rule. u -> p can be inferred via the biconditional elimination rule. p -> u can be inferred via the biconditional elimination rule. ~p can be inferred via the biconditional elimination rule.