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