Hi Stefano and thanks for the questions.

Will all individual diagrams have a unique solution - or - each diagram may have multiple solutions but when considered as part of the larger system (e.g. the pair of sudokus having the two-digit number in common) the solution will be unique?

In both parts 2 and 3, some of the puzzles will have multiple solutions, but only one solution will be accepted as correct and that is the one which is consistent with the complete solution of the whole set or the group of linked puzzles.

With this question you accidentally pointed out another mistake in the booklet...

You may have noticed there are three sudokus in the example for part 2, although in the instructions it is said that there are pairs of sudokus.

Well, that is because the sudokus in this part are grouped in triplets.

Sorry for this mistake, it will be corrected in the next update of IB, which will be uploaded tomorrow evening.

So, part 2 - three sudokus connected with the same two-digit number, having the same picture of a Smurf next to the grid.

The correct part is that there will be two puzzles on one page of puzzle booklet and the third connected sudoku will be on the next page. So a bit of scrolling for you to do in this part also.

Also: Will the position of the dwarfs around the snow white large diagram have any meanings (e.g. indicating in which row or column a certain digit will be) ? in the example it does not seems so.

The positions of the dwarfs around the snow white sudoku grid are crucial for solving this puzzle. It is explained on the front page of the part 3 IB and PB, but maybe not clear enough, so I'll try to explain it a little better.

What you first have to do is find out which number each dwarf stands for. Those are numbers 1-7. Then, when you look at the final puzzle, you'll see seven circles in the grid. This is where you have to place the dwarfs - 7 different numbers in 7 circles.

But to place them correctly you must look at the dwarfs around the grid. There are exactly two dwarfs next to some rows and columns, representing two numbers. One of those two dwarfs/numbers has to be placed in one of the circles in the corresponding row/column. The other one cannot be placed in any of the circles in the corresponding row/column.

I hope this makes a bit more clear.