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_1: ~T(y_1). forall y_1: R_3(y_1) -> T(y_1). forall y_1: S(y_1) -> T(y_1). exists y_1: S(y_1) or R_3(y_1).
forall y_1: ~R_3(y_1) can be inferred via the universal modus tollens rule. forall y_1: ~S(y_1) can be inferred via the universal modus tollens rule. exists y_1: T(y_1) can be inferred via the existential disjunction elimination rule.