I said just the other day, "Adding constraints that encode the additional rules is also a little puzzle, eh?" I think I see a kind of hierarchy that reminds me

I said just the other day, "Adding constraints that encode the additional rules is also a little puzzle, eh?" I think I see a kind of hierarchy that reminds me of the Futamura Projections: 1. Solving Sudoku puzzles. 2. Designing new Sudoku puzzles (with additional constraints even.) 3. Designing (e.g. CLP(FD/ℤ)) programs to solve all sudoku puzzles everywhere. - - - - How do you pronounce "ℤ" in this context? "see el pee eff dee zed"? Seems too plain. "see el pee eff dee Zahlen" seems too fancy. :-)