dailysudoku.com

[Angela]

I believed (wrongly, it seems) to have become quite an expert, but with this sudoku I just can't get on. Can anyone explain me AT LENGTH (because I dont't know the special names of the various techniques) how to get more numbers on it? I have only been able to add a 1, a 9 and a 6 to the starting scheme, and that's all!

Thank you very much!

[Angela]

I should have read the other messages on the topic of squigglies before asking (but try to understand me: I had been working on that sudoku, on and off, for three days!!). Anyway, I found Asellus' hint on the law of leftovers and I went to read it. I have solved the sudoku in a few minutes!!

Thank you very much!!

[sdq_pete]

Don't mention it! The "Left-over Law" [rule of subsets, I prefer to call it] is certainly the key to virtually every harder squiggly. I was on the point of giving up on squigglies until I discovered that!

Peter