[Earlier](https://news.ycombinator.com/item?id=11945254) you mention "good models of processes" and [elsewhere](https://news.ycombinator.com/item?id=11940688) about model building. Which models have been the best for you? Have you read [Robin Milner](http://www.cl.cam.ac.uk/archive/rm135/Bigraphs-draft.pdf)? Do you consider his work to be a good foundation for processes? If not, who do you consider to give a good foundation?