Consider the following premises. w -> p_24. p_24 -> w. forall x_23: ~R_23(x_23). ~p_24. t -> R_23(a_23). Can we infer t from them? If possible, name the inference rules being used at each step.
 From p_24 -> w, w -> p_24 we can infer p_24 <-> w via biconditional introduction. From forall x_23: ~R_23(x_23) we can infer ~R_23(a_23) via universal instantiation. From p_24 <-> w, ~p_24 we can infer ~w via biconditional elimination. Finally, from t -> R_23(a_23), ~R_23(a_23) we can infer ~t via modus tollens, which contradicts t. Therefore, the answer is no.