They let you write python programs as long as it’s from memory though. I wonder what the code golf looks like for a rudimentary python CAS. If you could evaluate the equation without needing to parse it, I bet you could get a lot of mileage out of a black box gradient decent routine. The analog circuit solver I wrote for my nSpire (without CAS) was ~11kB. https://github.com/deckar01/pylacc