"Dave Angel" <da...@davea.name> wrote in message news:551557b3.5090...@davea.name... > > But now I have to disagree about "true Sudoku puzzle." As we said > earlier, it might make sense to say that puzzles that cannot be solved > that way are not reasonable ones to put in a human Sudoku book. But why > isn't it a "true Sudoku puzzle"? >
It seems you are correct. According to Wikipedia http://en.wikipedia.org/wiki/Glossary_of_Sudoku - A puzzle is a partially completed grid. The initially defined values are known as givens or clues. A proper puzzle has a single (unique) solution. A proper puzzle that can be solved without trial and error (guessing) is known as a satisfactory puzzle. An irreducible puzzle (a.k.a. minimum puzzle) is a proper puzzle from which no givens can be removed leaving it a proper puzzle (with a single solution). It is possible to construct minimum puzzles with different numbers of givens. The minimum number of givens refers to the minimum over all proper puzzles and identifies a subset of minimum puzzles. So what I am talking about is called a "satisfactory" puzzle, which is a subset of a "proper" puzzle. Frank -- https://mail.python.org/mailman/listinfo/python-list
