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: exists x: U_1(x) -> Q(x). forall x: Q(x) <-> U_1(x). forall x: ~U_1(x).
forall x: Q(x) -> U_1(x) can be inferred via the universal biconditional elimination rule. forall x: U_1(x) -> Q(x) can be inferred via the universal biconditional elimination rule. forall x: ~Q(x) can be inferred via the universal biconditional elimination rule.