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: For all y_3, y_3 is rich if and only if y_3 will make tea.
For all y_3, if y_3 were rich, then y_3 is making tea can be inferred via the universal biconditional elimination rule. For all y_3, if y_3 makes tea, then y_3 is rich can be inferred via the universal biconditional elimination rule.