Consider the following premises. s <-> R_19(a_19). forall x_19: R_19(x_19) -> S_19(x_19). ~S_19(a_19). p -> s. Can we infer p from them? If possible, name the inference rules being used at each step.
 From forall x_19: R_19(x_19) -> S_19(x_19) we can infer R_19(a_19) -> S_19(a_19) via universal instantiation. From R_19(a_19) -> S_19(a_19), ~S_19(a_19) we can infer ~R_19(a_19) via modus tollens. From s <-> R_19(a_19), ~R_19(a_19) we can infer ~s via biconditional elimination. Finally, from p -> s, ~s we can infer ~p via modus tollens, which contradicts p. Therefore, the answer is no.