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: T(y) -> P_3(y). forall y: T(y) <-> P_3(y).
forall y: T(y) -> P_3(y) can be inferred via the universal biconditional elimination rule. forall y: P_3(y) -> T(y) can be inferred via the universal biconditional elimination rule.