What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? exists y: ~T_3(y). forall y: U(y) -> T_3(y). forall y: U(y) <-> T_3(y).
exists y: ~U(y). forall y: U(y) -> T_3(y). forall y: T_3(y) -> U(y). exists y: ~U(y).