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: w_3 <-> w_4. q -> w_4. t_1 or w_3. t_1 -> q.
t_1 -> w_4 can be inferred via the transitivity rule. w_3 -> w_4 can be inferred via the biconditional elimination rule. w_4 -> w_3 can be inferred via the biconditional elimination rule.