Consider the following premises. For all x, x will make tea or x is not excited. For all x, x will cook or x will not make tea. For all x, x is excited or x will not cook. Can we infer the following from them? For all x, x will make tea if and only if x is excited.
 From the fact that for all x, x will cook or x will not make tea we can infer that for all x, if x makes tea, then x is cooking. From the fact that for all x, x is excited or x will not cook we can infer that for all x, if x cooks, then x is excited. From the fact that for all x, x will make tea or x is not excited we can infer that for all x, if x were excited, then x is making tea. From the fact that for all x, if x makes tea, then x is cooking, and that for all x, if x cooks, then x is excited we can infer that for all x, if x makes tea, then x is excited. Finally, from the fact that for all x, if x makes tea, then x is excited, and that for all x, if x were excited, then x is making tea we can infer that for all x, x will make tea if and only if x is excited. Therefore, the answer is yes.