Consider the following premises. W(a_7) -> ~s. forall y: W(y) <-> R_1(y). s. Can we infer ~R_1(a_7) from them?
 From forall y: W(y) <-> R_1(y) we can infer W(a_7) <-> R_1(a_7). From W(a_7) -> ~s, s we can infer ~W(a_7). Finally, from W(a_7) <-> R_1(a_7), ~W(a_7) we can infer ~R_1(a_7). Therefore, the answer is yes.