You can discover more about a person in an hour of play than in a year of discussion. - Plato.
Okay, the rules state that if you are currently making an invention and someone else completes it that you can still finish it using the arrows to indicate which one you are working on. However, can I at a later point in the game also atart an invention that was completed a few rounds earlier. The rules would seem to suggest you can do this but how, (other than pencil and paper or an excellent memory) do you keep track of which inventions you have completed? Feedback is most welcome.