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_14(a_14). U(a_14) or r_3. forall x_14: U(x_14) <-> S_14(x_14).
forall x_14: U(x_14) -> S_14(x_14) can be inferred via the universal biconditional elimination rule. forall x_14: S_14(x_14) -> U(x_14) can be inferred via the universal biconditional elimination rule.