Consider the following premises. forall x_10: R_10(x_10) -> S_10(x_10). ~S_10(a_10). t <-> R_10(a_10). Can we infer t from them? If possible, name the inference rules being used at each step.
 From forall x_10: R_10(x_10) -> S_10(x_10) we can infer R_10(a_10) -> S_10(a_10) via universal instantiation. From R_10(a_10) -> S_10(a_10), ~S_10(a_10) we can infer ~R_10(a_10) via modus tollens. Finally, from t <-> R_10(a_10), ~R_10(a_10) we can infer ~t via biconditional elimination, which contradicts t. Therefore, the answer is no.