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 y: S_3(y) -> S_4(y). forall y: S_4(y) <-> W_3(y). forall y: W_4(y) -> S_4(y). forall y: P(y) -> S_3(y). exists y: P(y) or W_4(y).
forall y: P(y) -> S_4(y) can be inferred via the universal transitivity rule. forall y: S_4(y) -> W_3(y) can be inferred via the universal biconditional elimination rule. forall y: W_3(y) -> S_4(y) can be inferred via the universal biconditional elimination rule.