Hi, thanks for the encouragement, delayed response due focusing on the code, and a related conference, and now trying to keep up with the COP. As it happens, the “ratchet” system of pledges created in Paris (COP21) is an iterative algorithm - start with wild guesses and gradually improve them by feedback - this made sense given the weaknesses of diplomacy, but it’s hard to summarise this mess with neat code in a compact model.