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Earl · Joined: 30 May 2007 Posts: 677 Location: Victoria, KS

The Oct 7 VH offers a number of paths.
This solution is a one-stepper.

Solution: 136 xyz-wing

Early Earl

Marty R. · Posted: Wed Oct 07, 2009 3:47 am Post subject:

I didn't continue with the puzzle beyond the basics, but I saw three moves, each of which I considered a possibility for a one-stepper.

tlanglet · Posted: Wed Oct 07, 2009 5:06 am Post subject:

After basics:

Marty R. · Posted: Wed Oct 07, 2009 5:19 am Post subject:

Ted, from a terminology standpoint, the way I learned URs is a Type 6 involves an X-Wing on one of the deadly candidates, which does not exist here. So I'd call it an almost or potential Type 6, which doesn't detract from your excellent deductions.

tlanglet · Posted: Wed Oct 07, 2009 1:53 pm Post subject:

arkietech · Posted: Wed Oct 07, 2009 2:35 pm Post subject:

Good One!

Marty R. · Posted: Wed Oct 07, 2009 5:27 pm Post subject:

storm_norm · Joined: 18 Oct 2007 Posts: 1741

Wendy W · Joined: 04 Feb 2008 Posts: 144

I feel like an idiot saying this after all you smart folks have analyzed it, but since when does that ever stop me ... I really enjoyed today's puzzle! I thought it was way more of a challenge than usual.

keith · Posted: Wed Oct 07, 2009 11:44 pm Post subject:

tlanglet · Posted: Thu Oct 08, 2009 3:02 am Post subject:

keith · Posted: Thu Oct 08, 2009 6:51 am Post subject:

tlanglet · Posted: Thu Oct 08, 2009 12:35 pm Post subject:

keith · Posted: Thu Oct 08, 2009 2:49 pm Post subject:

Ted,

I think it's just semantics. In my description of the beast, I said that if you have a UR:

cgordon · Joined: 04 May 2007 Posts: 769 Location: ontario, canada

My understanding is that a Type 6 UR is like a diagonal version of a Type 4

Thus – if there are only two 3’s in Row 1 – you remove the 3 from the triple in the other row.

Marty R. · Posted: Fri Oct 09, 2009 12:33 am Post subject:

tlanglet · Posted: Fri Oct 09, 2009 2:42 pm Post subject:

The world is a wonderful, interesting and very confusing place. Sudoku semantics is a great example of "Confusion Reigns".

According to sudopedia.org/wiki, a hidden UR requires a strong link on one digit in both a row AND a column, with the common cell in the diagonal corner opposite the bivalue cell. (Note that the definition for a hidden UR does NOT require this common cell to be a bivalue.) Then, the deletion is the SECOND (OTHER) DIGIT of the common cell; not the digit with the strong links.

Therefore, as I view the murky world of Hidden URs, when your have the condition of two opposite bivalue cells in the Type 6 like arrangement, you can make deletions on either or both digit(s) but, because of the strong links, the end result is the same.

Anyone for a game of Hearts online?

Ted

Marty R. · Posted: Fri Oct 09, 2009 4:50 pm Post subject:

There's no doubt that Sudoku terminology is both interesting and confusing.

There's another kind of Hidden UR, but I can't locate the site where I saw it described. The two bivalue cells are in the same line and there's a strong link on one of the candidates, in the floor-to-ceiling cells. The other candidate is eliminated from the polyvalue cell in the other line.

Along these lines, I have come to regard the "Almost Type 6" as a 3rd type of Hidden UR, as it fits the pattern of the other two because the standard eliminations can't be made from the particular type of UR, but others can based on a strong link or two.

The three Hidden URs have in common the fact that eliminations can be made based on the pattern without further testing. URs that lead to eliminations because they serve as the starting points of XY- or Forcing Chains are not Hidden URs in my personal lexicon.

kragzy · Joined: 01 May 2007 Posts: 112 Location: Australia