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 y_3: W_3(y_3). forall y_3: P(y_3) -> T(y_3). forall y_3: W_3(y_3) <-> T(y_3).
forall y_3: W_3(y_3) -> T(y_3) can be inferred via the universal biconditional elimination rule. forall y_3: T(y_3) -> W_3(y_3) can be inferred via the universal biconditional elimination rule.