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: ~q_1. w -> t. q_1 -> w. t -> q_1.
~t can be inferred via the modus tollens rule. w -> q_1 can be inferred via the transitivity rule. q_1 -> t can be inferred via the transitivity rule. t -> w can be inferred via the transitivity rule.