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: forall x: W(x) <-> U(x). forall x: Q(x) -> W(x). exists x: Q(x).
exists x: W(x) can be inferred via the existential modus ponens rule. forall x: W(x) -> U(x) can be inferred via the universal biconditional elimination rule. forall x: U(x) -> W(x) can be inferred via the universal biconditional elimination rule.