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: t <-> s. s <-> q_3. w_4 -> q_3. ~t.
t -> s can be inferred via the biconditional elimination rule. s -> q_3 can be inferred via the biconditional elimination rule. s -> t can be inferred via the biconditional elimination rule. q_3 -> s can be inferred via the biconditional elimination rule. ~s can be inferred via the biconditional elimination rule.