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: p_2 <-> s_1. p_2 -> ~S_17(a_17). forall x_17: R_17(x_17) or S_17(x_17). ~R_17(a_17).
p_2 -> s_1 can be inferred via the biconditional elimination rule. s_1 -> p_2 can be inferred via the biconditional elimination rule.