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) <-> S_1(y). exists y: ~T_2(y).
forall y: T_2(y) -> S_1(y) can be inferred via the universal biconditional elimination rule. forall y: S_1(y) -> T_2(y) can be inferred via the universal biconditional elimination rule. exists y: ~S_1(y) can be inferred via the existential biconditional elimination rule.