What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: forall x_17: R_17(x_17) -> S_17(x_17). ~S_17(a_17) or p_2. R_17(a_17).
exists x: R_17(x) can be inferred via the existential generalization rule.