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. t -> q_4. p <-> t. t or ~q_4.
q_4 -> t can be inferred via the rewriting rule. p -> t can be inferred via the biconditional elimination rule. t -> p can be inferred via the biconditional elimination rule. ~t can be inferred via the biconditional elimination rule.