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_1 -> R_4(a). forall z: R_4(z) -> W(z). ~W(a). q_1 -> t_1. t_1 -> q_1.
q_1 -> R_4(a) can be inferred via the transitivity rule. q_1 <-> t_1 can be inferred via the biconditional introduction rule. t_1 <-> q_1 can be inferred via the biconditional introduction rule.