Consider the following premises. t -> p. p -> w. ~t. t or ~w. Can we infer w from them? If possible, name the inference rules being used at each step.
 From t -> p, p -> w we can infer t -> w via transitivity. From t or ~w we can infer w -> t via rewriting. From t -> w, w -> t we can infer t <-> w via biconditional introduction. Finally, from t <-> w, ~t we can infer ~w via biconditional elimination, which contradicts w. Therefore, the answer is no.