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 x: U_4(x) <-> T_3(x). T_3(h_4) <-> U_4(h_4).
T_3(h_4) -> U_4(h_4) can be inferred via the biconditional elimination rule. U_4(h_4) -> T_3(h_4) can be inferred via the biconditional elimination rule. forall x: U_4(x) -> T_3(x) can be inferred via the universal biconditional elimination rule. forall x: T_3(x) -> U_4(x) can be inferred via the universal biconditional elimination rule.