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keith
Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
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 Posted: Sat Apr 30, 2011 2:28 pm Post subject: Helmut Apr 09 Advanced |
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| Code: |
+-------+-------+-------+
| 7 . 2 | 6 . . | 4 . . |
| . 4 . | . . . | . . 2 |
| . . . | . 3 4 | . . 8 |
+-------+-------+-------+
| . . . | 9 . . | 1 5 4 |
| . 2 . | . . . | . 3 . |
| 1 9 5 | . . 6 | . . . |
+-------+-------+-------+
| 9 . . | 4 5 . | . . . |
| 2 . . | . . . | . 4 . |
| . . 4 | . . 8 | 2 . 6 |
+-------+-------+-------+
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Play this puzzle online at the Daily Sudoku site
I found an unusual one-stepper.
Hint: | Quote: | | Look closely at R12B23 |
Keith |
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Marty R.
Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
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| Posted: Sat Apr 30, 2011 7:21 pm Post subject: |
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I didn't read your hint beforehand, but probably had the same move. Flightless XYZ-Wing (159) with transport; r1c9<>1.
It took me forever to spot that and I didn't see one conventional move. I was ready to Medusa it when I spotted the wing. |
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keith
Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
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| Posted: Sat Apr 30, 2011 8:12 pm Post subject: |
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After basics: | Code: | +-------------------+-------------------+-------------------+
| 7 -1358 2 | 6 18e 159b | 4 19a 113 |
| 3568 4 13689 | 58 7 159 | 35 169 2 |
| 56 156 169 | 2 3 4 | 57 1679 8 |
+-------------------+-------------------+-------------------+
| 368 368 368 | 9 2 7 | 1 5 4 |
| 4 2 7 | 58 18d 15c | 6 3 9 |
| 1 9 5 | 3 4 6 | 8 2 7 |
+-------------------+-------------------+-------------------+
| 9 167 16 | 4 5 2 | 37 8 13 |
| 2 178 18 | 17 6 3 | 9 4 5 |
| 35 35 4 | 17 9 8 | 2 17 6 |
+-------------------+-------------------+-------------------+ |
Marty, that is very cool! It's not what I meant. I think you mean any cell that sees the triple abc 159 above cannot be 1. But, if c is 1, so is e, making the eliminations shown.
I don't see a flightless wing, since ab are not in the same box. Looks to me more like a bent triple with transport.
I suspect these are not very unusual, but we don't look for them.
Keith
Last edited by keith on Sat Apr 30, 2011 9:14 pm; edited 1 time in total |
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keith
Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
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| Posted: Sat Apr 30, 2011 8:18 pm Post subject: |
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What I did find: | Code: | +-------------------+-------------------+-------------------+
| 7 -1358 2 | 6 18A -159 | 4 -19 13B |
|3-568 4 13689 | 58D 7 1-59 | 35C 169 2 |
| 56 156 169 | 2 3 4 | 57 1679 8 |
+-------------------+-------------------+-------------------+
| 368 368 368 | 9 2 7 | 1 5 4 |
| 4 2 7 | 58 18 15 | 6 3 9 |
| 1 9 5 | 3 4 6 | 8 2 7 |
+-------------------+-------------------+-------------------+
| 9 167 16 | 4 5 2 | 37 8 13 |
| 2 178 18 | 17 6 3 | 9 4 5 |
| 35 35 4 | 17 9 8 | 2 17 6 |
+-------------------+-------------------+-------------------+ |
ABCD is a closed XY chain (a loop), making the eliminations shown.
AB eliminate 1 in their peers.
BC eliminate 3 in their peers.
CD eliminate 5 in their peers.
DA eliminate 8 in their peers.
Keith |
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Marty R.
Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
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| Posted: Sat Apr 30, 2011 9:43 pm Post subject: |
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| Quote: | I think you mean any cell that sees the triple abc 159 above cannot be 1. But, if c is 1, so is e, making the eliminations shown.
I don't see a flightless wing, since ab are not in the same box. Looks to me more like a bent triple with transport. |
Keith, I think we just have a semantics issue. I call it a wing because it has the form XYZ-XZ-YZ. I don't see it as a triple.
I like your loop. It's so simple but so hard to see. Did you see any more conventional moves? I didn't. |
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keith
Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
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| Posted: Sat Apr 30, 2011 9:59 pm Post subject: |
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Marty, you are probably correct about the terminology (semantics), since a triple makes eliminations in all the candidates, but a wing makes eliminations in one candidate only.
But, this is in three boxes. An XYZ-wing has two of its candidates in one box.
> Did you see any more conventional moves? I didn't.
No, I did not. There are chains that make the loop's eliminations one at a time, but I did not see any simpler moves.
So, we wonder: What did Helmut (Nataraj) have in mind?
Keith |
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Asellus
Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA
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| Posted: Sat Apr 30, 2011 10:22 pm Post subject: |
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Marty's solution is also a closed loop and makes an additional elimination:
159ALS[(1)r1c68=(5)r1c6] - (5=1)r5c6 - (1)r5c5=(1)r1c5 - Loop; r1c29<>1|r2c6<>5
Note that it would also eliminate <9>s from other cells in row 1 if there were any.
The same eliminations can also be seen as a 1589 Sue de Coq in r1c568|r2c4. |
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daj95376
Joined: 23 Aug 2008
Posts: 3854
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| Posted: Sat Apr 30, 2011 11:21 pm Post subject: |
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| keith wrote: | So, we wonder: What did Helmut (Nataraj) have in mind?
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Wasn't he fond of the M-Wing?
| Code: | +-----------------------------------------------------------------------+
| 7 1358 2 | 6 18 159 | 4 19 13 |
| 3568 4 13689 | 58 7 159 | 35 169 2 |
| 56 156 169 | 2 3 4 | 57 1679 8 |
|-----------------------+-----------------------+-----------------------|
| 368 368 368 | 9 2 7 | 1 5 4 |
| 4 2 7 | 58 18 15 | 6 3 9 |
| 1 9 5 | 3 4 6 | 8 2 7 |
|-----------------------+-----------------------+-----------------------|
| 9 167 16 | 4 5 2 | 37 8 13 |
| 2 178 18 | 17 6 3 | 9 4 5 |
| 35 35 4 | 17 9 8 | 2 17 6 |
+-----------------------------------------------------------------------+
# 52 eliminations remain
M-Wing 7A (5=3)r2c7 - r1c9 = (3-5)r1c2 = (5)r1c6 => r2c46<>5
M-Wing 7B (5=3)r2c7 - r2c13 = (3-5)r1c2 = (5)r1c6 => r2c46<>5
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Marty R.
Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
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| Posted: Sun May 01, 2011 12:35 am Post subject: |
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| Quote: | | So, we wonder: What did Helmut (Nataraj) have in mind? |
I messaged him, so maybe he'll come over and tell us. |
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keith
Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
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| Posted: Sun May 01, 2011 12:46 am Post subject: |
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| daj95376 wrote: | | keith wrote: | So, we wonder: What did Helmut (Nataraj) have in mind?
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Wasn't he fond of the M-Wing? |
Yes, an M-wing is often the key to his "Advanced" puzzles. I looked, but did not see the ones you point out in this puzzle.
Possibly, I fell in love with the loop.
Keith |
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daj95376
Joined: 23 Aug 2008
Posts: 3854
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| Posted: Sun May 01, 2011 12:53 am Post subject: |
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[Withdrawn: too much!]
Last edited by daj95376 on Sun May 01, 2011 4:14 am; edited 1 time in total |
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keith
Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
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| Posted: Sun May 01, 2011 1:12 am Post subject: |
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| Asellus wrote: | | Marty's solution is also a closed loop |
I suspect that all of these transported XYZ-wings are loops, since the pincered cell must be in the same house as two of the others in the chain.
We won't know until someone defines them and writes the theory.
I remain in awe that these simple constructs are just sitting there, unrecognized. I mean, if you can see an M-wing (or a half gM-wing), isn't Marty's pattern simpler?
Keith |
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Asellus
Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA
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| Posted: Sun May 01, 2011 9:21 am Post subject: |
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| keith wrote: | | I suspect that all of these transported XYZ-wings are loops, since the pincered cell must be in the same house as two of the others in the chain. |
In my experience, transported "XYZ-Wing" pincers (actually 2-ALS pincers) do not usually form continuous loops. ("Closed" is really a misnomer. All AICs are actually loops and are thus "closed." The distinction is in whether an AIC loop is continuous or discontinuous.) Here's a similar example found in a grid in a neighboring thread:
| Code: | +----------------+----------------+----------------+
| 8 3 1 | 49 6 5 | 2 7 #49 |
| 9 7 4 | 2 38 13 | 6 5 18 |
| 6 5 2 | 489 7 b149 |a14 3 #1489 |
+----------------+----------------+----------------+
| 7 4 9 | 3 2 8 | 5 1 6 |
| 3 1 8 | 5 4 6 | 7 9 2 |
| 2 6 5 | 1 9 7 | 8 4 3 |
+----------------+----------------+----------------+
| 15 2 3 | 489 58 c49 |#14 6 7 |
| 4 9 7 | 6 1 2 | 3 8 5 |
| 15 8 6 | 7 35 34 | 9 2 d14 |
+----------------+----------------+----------------+ |
The XYZ-Wing-like 2-ALS is in abc. The <4>s in bc are transported to d, eliminating <4>s in the cells # (a discontinuous loop).
(4=1)r3c7 - ALS[(1)r3c6=(4)r37c6] - (4)r9c6=(4)r9c9; r7c7|r13c9<>4
(You could also see it as transporting the <4> at a to d, thus eliminating <4> from r9c6. It amounts to the same thing.)
Thinking of it as XYZ-Wing-like and "transporting pincers" is just another way to find an AIC containing an ALS strong inference. Sometimes the AIC will form a continuous loop, but usually not. |
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tlanglet
Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
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| Posted: Sun May 01, 2011 1:50 pm Post subject: |
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I realize that many do not consider an AUR as a conventional move, but..........
AUR(19)r12c68 mixed sis r12c6=5,r3c8=9; r1c29<>1
(1=9)r1c8-AUR(19)r12c68[(9)r3c8]=(5)r12c6]-(5=1)r5c6-r5c5=(1)r1c5;
Ted |
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nataraj
Joined: 03 Aug 2007
Posts: 1048
Location: near Vienna, Austria
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| Posted: Tue May 03, 2011 8:33 pm Post subject: |
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| keith wrote: | | daj95376 wrote: | | keith wrote: | So, we wonder: What did Helmut (Nataraj) have in mind?
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Wasn't he fond of the M-Wing? |
Yes, an M-wing is often the key to his "Advanced" puzzles. I looked, but did not see the ones you point out in this puzzle.
Possibly, I fell in love with the loop.
Keith |
Indeed, I am quite fond of the m-wing.
In this puzzle, there is one (5)r1c6=r2c7 via the SL (3) in row 1 and it removes 5 from r2c46. And another one - Danny pointed out the two m-wings in his post.
I am sorry I don't come here more often ... today I logged on in order to tell you that I made a major technical upgrade in the sudok-o-rama. It will not send a whole bunch of data at the beginning, but just today's puzzles and then load more puzzles as they are requested. Pretty much changed the whole underlying data management - to SQL and AJAX if anyone is into that sort of thing. who knows, maybe PAMPERS will be next 
I do hope you guys have no troubles with the new version, since I'll be on vacation starting day after tomorrow - two weeks in the sunny Canary islands mmmhhhh  )
BTW, no m-wing Thursday, Friday this week, nor Monday next week, far as I can see... |
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keith
Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
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| Posted: Wed May 04, 2011 1:14 am Post subject: |
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Marty's Wing
This is quite remarkable.
| Code: |
+---------+---------+---------+
| . / . | . . . | . . . |
| . aX . | . XYZ . | . XY . |
| . / . | . . . | . . . |
+---------+---------+---------+
| . / . | . . . | . . . |
| . / . | . . . | . . . |
| . / . | . . . | . . . |
+---------+---------+---------+
| . bX . | . XZ . | . . . |
| . / . | . . . | . . . |
| . / . | . . . | . . . |
+---------+---------+---------+
X, Y, Z - Specific candidates
. - Any candidates
a, b - Any candidates other than X
/ - Does not contain X |
What are the possible eliminations? How about:
| Code: | +----------+-----------+-----------+
| . / . | . -Z . | . . . |
|-XY aX -XY|-XY XYZ -XY|-XY XY -XY|
| . / . | . -Z . | . . . |
+----------+-----------+-----------+
| . / . | . -Z . | . . . |
| . / . | . -Z . | . . . |
| . / . | . -Z . | . . . |
+----------+-----------+-----------+
| -X bX -X| -X XZ -X| -X -X -X|
| . / . | . -Z . | . . . |
| . / . | . -Z . | . . . |
+----------+-----------+-----------+ |
(Edit: Corrected to show there are not eliminations in R3C8. Note also, as pointed out by ronk below, that Y is eliminated from R2C2.)
Here are the three possible solutions:
| Code: | +---------+---------+---------+
| . / . | . . . | . . . |
| . a . | . X . | . Y . |
| . / . | . . . | . . . |
+---------+---------+---------+
| . / . | . . . | . . . |
| . / . | . . . | . . . |
| . / . | . . . | . . . |
+---------+---------+---------+
| . X . | . Z . | . . . |
| . / . | . . . | . . . |
| . / . | . . . | . . . |
+---------+---------+---------+
+---------+---------+---------+
| . / . | . . . | . . . |
| . a . | . Y . | . X . |
| . / . | . . . | . . . |
+---------+---------+---------+
| . / . | . . . | . . . |
| . / . | . . . | . . . |
| . / . | . . . | . . . |
+---------+---------+---------+
| . X . | . Z . | . . . |
| . / . | . . . | . . . |
| . / . | . . . | . . . |
+---------+---------+---------+
+---------+---------+---------+
| . / . | . . . | . . . |
| . X . | . Z . | . Y . |
| . / . | . . . | . . . |
+---------+---------+---------+
| . / . | . . . | . . . |
| . / . | . . . | . . . |
| . / . | . . . | . . . |
+---------+---------+---------+
| . b . | . X . | . . . |
| . / . | . . . | . . . |
| . / . | . . . | . . . |
+---------+---------+---------+ |
and the eliminations follow.
Keith
Last edited by keith on Thu May 05, 2011 7:37 pm; edited 1 time in total |
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keith
Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
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| Posted: Thu May 05, 2011 12:43 am Post subject: |
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It's like deja vu, all over again.
(I thought I saw a post by Danny.)
Anyway, if you can imagine there was such a post, you can imagine my response would be:
Your efforts to write my example in chain notation help me to articulate my problem with all of these Sudoku notations. They are, simply, not general enough.
They are mostly almost adequate to point out a deduction in a particular puzzle. They are not adequate to describe a general pattern.
For example, today's puzzle: After basics:
| Code: | +----------------+----------------+----------------+
| 8 1 2 | 7 5 69 | 4 3 69 |
| 36b 4 7 | 39a 8 2 | 59 15 1569 |
| 356 56 9 | 34 1 46 | 2 7 8 |
+----------------+----------------+----------------+
| 69c 8 3 |4-9 2 5 | 1 46 7 |
| 29 7 4 | 1 6 3 | 59 8 259 |
| 1 26 5 | 8 7 49 | 3 46 29 |
+----------------+----------------+----------------+
| 4 3 6 | 2 9 7 | 8 15 15 |
| 7 9 1 | 5 3 8 | 6 2 4 |
| 25 25 8 | 6 4 1 | 7 9 3 |
+----------------+----------------+----------------+ |
It is easy to write a chain in Eureka or whatever notation for this example of the XY-wing that takes out 9 in R4C4.
But, how do you write an expression for XZ-XY-YZ eliminates Z in the shared peers of XZ and YZ? And, which also transmits the idea that XZ and YZ are not peers, so this is not a simple triple?
And, do it in such a way that someone can take the chain and unambiguously construct the pattern on a Sudoku grid.
Keith |
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ronk
Joined: 07 May 2006
Posts: 398
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| Posted: Thu May 05, 2011 1:10 am Post subject: |
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| keith wrote: | | ... how do you write an expression for XZ-XY-YZ eliminates Z in the shared peers of XZ and YZ? And, which also transmits the idea that XZ and YZ are not peers, so this is not a simple triple? |
I'm assuming those are rhetorical questions. |
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daj95376
Joined: 23 Aug 2008
Posts: 3854
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| Posted: Thu May 05, 2011 2:29 am Post subject: |
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| keith wrote: | But, how do you write an expression for XZ-XY-YZ eliminates Z in the shared peers of XZ and YZ? And, which also transmits the idea that XZ and YZ are not peers, so this is not a simple triple?
And, do it in such a way that someone can take the chain and unambiguously construct the pattern on a Sudoku grid.
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Yes, I made a post and removed it. As for the two parts of your first question.
(Z=X)cell_a - (X=Y)cell_b - (Y=Z)cell_c => elimination of Z in peers of cell_a and cell_c
I do not add "- loop".
You'll notice that I don't "sort" candidates used in my chains. Reading your chains written as XZ-XY-YZ are not accurate. It also took awhile to realize that when you wrote something like XZ=XY=YZ that you required the weak inferences to be satisfied by strong links. |
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keith
Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
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| Posted: Thu May 05, 2011 2:49 am Post subject: |
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| ronk wrote: | | keith wrote: | | ... how do you write an expression for XZ-XY-YZ eliminates Z in the shared peers of XZ and YZ? And, which also transmits the idea that XZ and YZ are not peers, so this is not a simple triple? |
I'm assuming those are rhetorical questions. |
No, they are not.
Please write Marty's loop (edit:) as described by me (end edit) in the notation of your choice.
Keith
Last edited by keith on Thu May 05, 2011 3:14 am; edited 1 time in total |
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