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_2(y) -> ~T(y). forall y: T(y). forall y: T_2(y) <-> R(y).
exists y: ~T_2(y) can be inferred via the existential modus tollens rule. forall y: T_2(y) -> R(y) can be inferred via the universal biconditional elimination rule. forall y: R(y) -> T_2(y) can be inferred via the universal biconditional elimination rule.