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 x: T(x) <-> P_1(x). forall x: U(x) or Q_4(x). forall x: ~P_1(x). forall x: T(x) <-> U(x).
forall x: T(x) -> U(x) can be inferred via the universal biconditional elimination rule. exists x: T(x) -> P_1(x) can be inferred via the existential biconditional elimination rule. forall x: U(x) -> T(x) can be inferred via the universal biconditional elimination rule. exists x: P_1(x) -> T(x) can be inferred via the existential biconditional elimination rule. exists x: ~T(x) can be inferred via the existential biconditional elimination rule.