Sigh classic LLM -- without you, the expert, I can't quickly tell from the code / output how the answer the LLM produced is wrong. I also asked it to solve sudoku by "propagating constraints" and the answer seemed to work for me :/ Again, I'd guess the soln produced is wrong because I trust you more than the LLM but I don't have the mental horsepower to figure it out without resorting to tests & debugging.