Consider the following premises. ~S_11(g). forall x_11: R_11(x_11) <-> S_11(x_11). u_2 -> t. ~t. Can we infer R_11(g) from them? If possible, name the inference rules being used at each step.
 From u_2 -> t, ~t we can infer ~u_2 via modus tollens. From forall x_11: R_11(x_11) <-> S_11(x_11) we can infer R_11(g) <-> S_11(g) via universal instantiation. Finally, from R_11(g) <-> S_11(g), ~S_11(g) we can infer ~R_11(g) via biconditional elimination, which contradicts R_11(g). Therefore, the answer is no.