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: T_2(y) -> T(y). forall y: T(y) -> T_2(y). exists y: T(y) or W_1(y). forall y: ~T_2(y).
forall y: ~T(y) can be inferred via the universal modus tollens rule. forall y: T_2(y) <-> T(y) can be inferred via the universal biconditional introduction rule. forall y: T(y) <-> T_2(y) can be inferred via the universal biconditional introduction rule.