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: U(h_2). forall y: W(y) or ~U(y).
exists x: U(x) can be inferred via the existential generalization rule. forall y: U(y) -> W(y) can be inferred via the universal rewriting rule.