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(y). exists y: P_4(y) -> W_4(y). forall y: S(y) -> P_4(y). forall y: P(y) <-> P_4(y).
forall y: P_4(y) can be inferred via the universal modus ponens rule. exists y: S(y) -> W_4(y) can be inferred via the existential transitivity rule. forall y: P(y) -> P_4(y) can be inferred via the universal biconditional elimination rule. forall y: P_4(y) -> P(y) can be inferred via the universal biconditional elimination rule.