Consider the following premises. forall x_16: R_16(x_16) <-> S_16(x_16). ~p_8 -> s. p_8 <-> R_16(a_16). ~S_16(a_16). Can we infer ~s from them? If possible, name the inference rules being used at each step.
 From forall x_16: R_16(x_16) <-> S_16(x_16) we can infer R_16(a_16) <-> S_16(a_16) via universal instantiation. From R_16(a_16) <-> S_16(a_16), ~S_16(a_16) we can infer ~R_16(a_16) via biconditional elimination. From p_8 <-> R_16(a_16), ~R_16(a_16) we can infer ~p_8 via biconditional elimination. Finally, from ~p_8 -> s, ~p_8 we can infer s via modus ponens, which contradicts ~s. Therefore, the answer is no.