[duvenaud]

Thanks for the kind words! I would agree that the function we're trying to learn is very complicated, with many exceptions. But that only improves our comparative advantage, at least compared to novice chemists. We might also be able to help our system take advantage of the knowledge of physics that expert chemists use to predict reaction outcomes by giving our network access to the output of a physical reaction simulator.

Extending the system to (try to) predict yield percentages or chirality is straightforward. The hard part, in my mind, is that there aren't a fixed number of reaction types. As molecules get bigger, we'll have to move away from predicting one of a fixed set of reaction types, to directly predicting products - but this is a much harder problem.

Our system probably isn't good enough to design synthesis pathways yet, but that is the eventual goal. A system that also predicted yield would of course help with that, and that would be another straightforward extension.