Sudoku Players' Forum (clone)

I have gotten to this point but am not seeing any way to move further without T&E

792 **5 *63
*1* **7 5*9
*5* *39 *7*

*8* *** 352
*** *5* ***
5*1 *** *4*

*7* 968 ***
8** 5** *9*
*4* *** 8**

You should take a really good look at row 9. And after that you should ook at column 1. (After removing some candidates that is)

I still don't see it
I'm showing the following for R9

{12369} {4} {3569} {1237} {127} {123} {8} {123} {1567}

Well exactly. Not having done it myself, and therefore assuming your working is correct: why don't you discount all references to candidates 1,2,3 and 7 in cells 1,3 and 9? Haven't you spotted the quad relationship in cells 4,5,6 and 8? No problem if you haven't, but I suggest you read some of the method/technique files belonging to simes or angus.

Good luck with the rest of it.

Thanks...... I guess I was not expecting Quads from Pappocom. I think I understand it now. I hope at some point I can spot them as easily as pairs and triples.

Quads are not necessary for solving Pappocom puzzles. If they exist and you can find 'em, then make use of them, by all means - but somewhere there will be a simpler way.

- Wayne

It does look like row 9 is the key to solving this puzzle. It's a little amusing that the {1237} quad is easier to spot than the {569} triple.

Actually, I was a bit hasty in my last reply. I should have said that Quads are not necessary to solve this puzzle.

It is possible to have a Pappocom puzzle where you must use Quads in order to make progress - but only in Very Hard puzzles.

- Wayne