Consider the following premises. For all x, if x makes tea, then x is taking a plane. For all x, if x takes a plane, then x is making tea. For all x, x will not take a plane. Can we infer the following from them? If we can, name the inference rule being used: For all x, x will not make tea.
 From the fact that for all x, if x makes tea, then x is taking a plane, and that for all x, if x takes a plane, then x is making tea we can infer that for all x, x will make tea if and only if x will take a plane via universal biconditional introduction. Finally, from the fact that for all x, x will make tea if and only if x will take a plane, and that for all x, x will not take a plane we can infer that for all x, x will not make tea via universal biconditional elimination. Therefore, the answer is yes.