I think every suggestion you have there would fall under that very same lamppost: a linear model of computation going only one direction. Sussman details in thi

I think every suggestion you have there would fall under that very same lamppost: a linear model of computation going only one direction. Sussman details in this talk a different model he calls propagators that deal with information flow back and forth, allowing for some interesting ways of working with "fuzzy" and incomplete data, while still allowing for cheap backtracking if a contradiction arises. I haven't read the Radul & Sussman's paper "The Art of the Propagator"[1] yet, but I fully intend to now having watched the talk. [1]: 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...