Briefly glancing through the slides, this appears to be based on the work in "The Art of the Propagator" by Alexey Radul and Gerald Jay Sussman. [PDF] https://

Briefly glancing through the slides, this appears to be based on the work in "The Art of the Propagator" by Alexey Radul and Gerald Jay Sussman. [PDF] https://dspace.mit.edu/bitstream/handle/1721.1/44215/MIT-CSAIL-TR-2009-002.pdf https://dspace.mit.edu/bitstream/handle/1721.1/44215/MIT-CSA... See also the recent discussion: https://news.ycombinator.com/item?id=20405183 https://news.ycombinator.com/item?id=20405183