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: q_11. forall x: U_4(x) -> W(x). forall x: W(x) -> U_4(x). U_4(a_16) -> ~q_11.
~U_4(a_16) can be inferred via the modus tollens rule. forall x: U_4(x) <-> W(x) can be inferred via the universal biconditional introduction rule. forall x: W(x) <-> U_4(x) can be inferred via the universal biconditional introduction rule.