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: P(x) or U(x). forall x: P_4(x) <-> W(x). forall x: W(x) <-> P(x). forall x: ~P_4(x).
forall x: P_4(x) -> W(x) can be inferred via the universal biconditional elimination rule. forall x: W(x) -> P(x) can be inferred via the universal biconditional elimination rule. forall x: W(x) -> P_4(x) can be inferred via the universal biconditional elimination rule. forall x: P(x) -> W(x) can be inferred via the universal biconditional elimination rule. forall x: ~W(x) can be inferred via the universal biconditional elimination rule.