This is a really nice post and I especially liked the vulnerability in the conclusion about not being able to generate puzzles quickly because of how you ordere

This is a really nice post and I especially liked the vulnerability in the conclusion about not being able to generate puzzles quickly because of how you ordered your constraints - I get stuck there almost every time I write Prolog. One thing to nitpick is that the number operators (#>) require an import of clpfd, so some readers may not be able to get the code examples to work.