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daj95376
Joined: 23 Aug 2008
Posts: 3854
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 Posted: Thu Apr 09, 2009 6:01 pm Post subject: Set T_03 Puzzle 38 |
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VH+ ... and probably very difficult
| Code: | +-----------------------+
| 6 . . | . . 2 | . . 1 |
| . 8 4 | . 1 . | . 2 . |
| . 1 3 | . . . | . . 4 |
|-------+-------+-------|
| . . . | 1 . . | 7 . . |
| . 7 . | . 5 . | 4 . 8 |
| 4 . . | . . 8 | . . . |
|-------+-------+-------|
| . . . | 5 3 . | 8 6 . |
| . 6 . | . . . | 5 . 3 |
| 3 . 5 | . 8 . | . 4 7 |
+-----------------------+
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Play this puzzle online at the Daily Sudoku site
| Code: | c7b3 Locked Triple <> 369 [r13c8],[r2c9],[r69c7]
Empty Rectangle c8b4 <> 1 [r8c3]
Empty Rectangle c7b7 <> 2 [r6c3]
Empty Rectangle r5b8 <> 2 [r8c3]
Empty Rectangle r5b7 <> 2 [r9c4] extraneous
c3 Naked Pair <> 79 [r567c3]
r7 b7 Locked Candidate 1 <> 1 [r7c6]
XY-Wing [r9c7]/[r8c8]+[r9c2] <> 9 [r8c3]
turbot fish/ER c1b9 <> 9 [r5c8]
XY-Wing [r5c8]/[r4c8]+[r5c1] <> 9 [r4c2]
turbot fish/ER r7b4 <> 9 [r6c9]
r6 Naked Triple <> 126 [r6c245]
r4 b6 Locked Candidate 1 <> 9 [r4c56]
r6 b6 Locked Candidate 2 <> 2 [r4c9]
XY-Wing [r6c3]/[r6c9]+[r7c3] <> 2 [r7c9]
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Last edited by daj95376 on Thu Apr 16, 2009 5:00 pm; edited 1 time in total |
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tlanglet
Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
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| Posted: Thu Apr 09, 2009 7:33 pm Post subject: Re: Set T_03 Puzzle 38 |
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| daj95376 wrote: | | VH+ ... and probably very difficult |
and long.......
I seem to find possibilities, but I had to do clean-up regularly. My ten steps were as follows: | Quote: | kite 1
finned x-wing 2
ER 2
xy-wing 129
w-wing 79 with a grouped strong link in row7,
UR 78 with X-wing 8 overlay,
w-wing 29 provided a deletion plus two more transports for two more deletions,
skyscraper with a transport,
Sashimi x-wing 9,
xy-wing 139
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Ted  |
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gindaani
Joined: 06 Mar 2009
Posts: 79
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| Posted: Thu Apr 09, 2009 10:57 pm Post subject: |
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I really enjoyed this one.
After the basics:
| Code: |
+--------------+-----------------+-------------+
| 6 5 79 | 34789 479 2 | 39 78 1 |
| 79 8 4 | 3679 1 3679 | 369 2 5 |
| 2 1 3 | 6789 679 5 | 69 78 4 |
+--------------+-----------------+-------------+
| 5 239 8 | 1 2469 3469 | 7 39 269 |
| 19 7 1269 | 2369 5 369 | 4 139 8 |
| 4 239 1269 | 23679 2679 8 | 12 5 269 |
+--------------+-----------------+-------------+
| 179 4 1279 | 5 3 179 | 8 6 29 |
| 8 6 1279 | 2479 2479 1479 | 5 19 3 |
| 3 29 5 | 269 8 169 | 12 4 7 |
+--------------+-----------------+-------------+
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Play this puzzle online at the Daily Sudoku site
One step solution:
| Quote: | 129 xy-wing with transported pincer => r7c1<>9, r46c2<>9
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tlanglet
Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
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| Posted: Fri Apr 10, 2009 9:31 pm Post subject: |
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Really great move Gindaani 
Ted |
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Marty R.
Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
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| Posted: Tue Apr 14, 2009 3:55 pm Post subject: |
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| gindaani wrote: | I really enjoyed this one.
After the basics:
| Code: |
+--------------+-----------------+-------------+
| 6 5 79 | 34789 479 2 | 39 78 1 |
| 79 8 4 | 3679 1 3679 | 369 2 5 |
| 2 1 3 | 6789 679 5 | 69 78 4 |
+--------------+-----------------+-------------+
| 5 239 8 | 1 2469 3469 | 7 39 269 |
| 19 7 1269 | 2369 5 369 | 4 139 8 |
| 4 239 1269 | 23679 2679 8 | 12 5 269 |
+--------------+-----------------+-------------+
| 179 4 1279 | 5 3 179 | 8 6 29 |
| 8 6 1279 | 2479 2479 1479 | 5 19 3 |
| 3 29 5 | 269 8 169 | 12 4 7 |
+--------------+-----------------+-------------+
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Play this puzzle online at the Daily Sudoku site
One step solution:
129 xy-wing with transported pincer => r7c1<>9, r46c2<>9 |
Maybe I'm missing something, but I don't see the pincer transport possibility. The XY takes out only the 9 from r8c3 and there are too many 9s to allow transport.
I used the XY on 129, then an apparently useless UR on 78, three ERs and a 291 XY with pincer transport. |
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gindaani
Joined: 06 Mar 2009
Posts: 79
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| Posted: Tue Apr 14, 2009 4:48 pm Post subject: |
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The strong link on ones in column 8 provides the transport.
129 xy-wing in Eureka is (9=2)r9c2 - (2=1)r9c7 - (1=9)r8c8
Transport is (1=1)r58c8 - (1=9)r5c1
Combining gives (9=2)r9c2 - (2=1)r9c7 - (1=1)r58c8 - (1=9)r5c1 |
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Marty R.
Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
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| Posted: Tue Apr 14, 2009 5:06 pm Post subject: |
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Thanks, but I'm not a notation guy.  |
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gindaani
Joined: 06 Mar 2009
Posts: 79
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| Posted: Tue Apr 14, 2009 5:29 pm Post subject: |
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| Code: |
+-----------------+--------------------+----------------+
| 6 5 79 | 34789 479 2 | 39 78 1 |
| 79 8 4 | 3679 1 3679 | 369 2 5 |
| 2 1 3 | 6789 679 5 | 69 78 4 |
+-----------------+--------------------+----------------+
| 5 *239 8 | 1 2469 3469 | 7 39 269 |
| d19 7 1269 | 2369 5 369 | 4 c139 8 |
| 4 *239 1269 | 23679 2679 8 | 12 5 269 |
+-----------------+--------------------+----------------+
| *179 4 1279 | 5 3 179 | 8 6 29 |
| 8 6 1279 | 2479 2479 1479 | 5 b19 3 |
| 3 e29 5 | 269 8 169 | a12 4 7 |
+-----------------+--------------------+----------------+
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The strong link on 1 at b and c provides the transport.
If a=1, b != 1, c=1, d=9
If a=2, e=9
Cells marked * can see both d and e cannot be 9 |
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daj95376
Joined: 23 Aug 2008
Posts: 3854
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| Posted: Tue Apr 14, 2009 5:44 pm Post subject: |
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| gindaani wrote: | The strong link on ones in column 8 provides the transport.
129 xy-wing in Eureka is (9=2)r9c2 - (2=1)r9c7 - (1=9)r8c8
Transport is (1=1)r58c8 - (1=9)r5c1
Combining gives (9=2)r9c2 - (2=1)r9c7 - (1=1)r58c8 - (1=9)r5c1 |
I believe you mean.
| Code: | 129 xy-wing: (9=2)r9c2 - (2=1)r9c7 - (1=9)r8c8
Transport linkage: (1)r8c8 = (1)r5c8 - (1=9)r5c1
Combined: (9=2)r9c2 - (2=1)r9c7 - (1)r8c8 = (1)r5c8 - (1=9)r5c1
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----- ----- -----
Marty:
| Code: | XY-Wing w/vertex [r9c7]=12 forces pincers [r9c2]=9 or [r8c8]=9
[r8c8]=9 => [r8c8]<>1, [r5c8]=1, [r5c1]<>1, [r5c1]=9
if [r9c2]<>9 then [r5c1]=9 => [r46c2]<>9, [r7c1]<>9
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gindaani
Joined: 06 Mar 2009
Posts: 79
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| Posted: Tue Apr 14, 2009 6:05 pm Post subject: |
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| daj95376 wrote: | I believe you mean.
| Code: | 129 xy-wing: (9=2)r9c2 - (2=1)r9c7 - (1=9)r8c8
Transport linkage: (1)r8c8 = (1)r5c8 - (1=9)r5c1
Combined: (9=2)r9c2 - (2=1)r9c7 - (1)r8c8 = (1)r5c8 - (1=9)r5c1
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Sudopedia says "When groups of cells are used in the chain, they are named in the most efficient way." They go on to show that if all candidates are in one column, you can combine them. So (1)r8c8 = (1)r5c8 can be (1)r58c8. I personally prefer to combine the row column specification, but leave the hard link explicit, therefore (1=1)r58c8.
So, both notations are correct and differ only in their succinctness. |
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Marty R.
Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
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| Posted: Tue Apr 14, 2009 6:47 pm Post subject: |
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| OK, thank you. In my little world that wouldn't be a pincer transport. If c = 1, then d = 9. If b =1, then e = 9, thus the pincers. It just seems to me that it's a standalone technique that can be used without an XY-Wing. But regardless of the semantics, it's a very nice move. |
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gindaani
Joined: 06 Mar 2009
Posts: 79
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| Posted: Tue Apr 14, 2009 7:04 pm Post subject: |
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| Marty R. wrote: | | It just seems to me that it's a standalone technique that can be used without an XY-Wing. |
All xy-wings are xy-chains of 3 cells. Transporting the pincer is simply adding to the chain. In this case, the chain has 5 cells. So, you could call it a chain, which is what you are describing (I think). Some people find it easier to think of, and find, if they refer to it as an xy-wing with transported pincer.
| Marty R. wrote: | | But regardless of the semantics, it's a very nice move. |
Thanks! I had fun finding it, and explaining it. |
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daj95376
Joined: 23 Aug 2008
Posts: 3854
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| Posted: Tue Apr 14, 2009 7:29 pm Post subject: |
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| gindaani wrote: | Sudopedia says "When groups of cells are used in the chain, they are named in the most efficient way." They go on to show that if all candidates are in one column, you can combine them. So (1)r8c8 = (1)r5c8 can be (1)r58c8. I personally prefer to combine the row column specification, but leave the hard link explicit, therefore (1=1)r58c8.
So, both notations are correct and differ only in their succinctness. |
I had to read the Sudopedia link several times in order to make sense of it. I finally decided that they left out a few words and used incomplete examples.
----- ----- ----- ----- my proposal for Sudopedia examples
When groups of cells are used in the chain, they are named in the most efficient way.
All cells in the group belong to a single row:
(1)r5c456 = (1)r5c9
All cells in the group belong to a single column:
(1)r45c4 = (1)r9c4
Unordered group, in a box: (not sure how to use this segment)
(1)r5c1 - (1)r5c4|r6c45 - (1)r6c9
-or-
(1)r5c1 - (1)r5c4=r6c45 - (1)r6c9
----- ----- ----- -----
Except for the example in a box, the group of cells does not exhaust the candidate in all of the cells of a house/unit.
Your (1=1)r58c8 exhausts <1> in [c8] ... and that's why I had a problem with it.
I would have accepted:
Transport linkage: (1)r8c8=r5c8 - (1=9)r5c1 |
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gindaani
Joined: 06 Mar 2009
Posts: 79
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| Posted: Tue Apr 14, 2009 7:46 pm Post subject: |
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| daj95376 wrote: | | Your (1=1)r58c8 exhausts <1> in [c8] ... and that's why I had a problem with it. |
That statement is supposed to exhaust <1> in [c8]. If you look, the only <1> in [c8] are [r5c8] and [r8c8].
If there was another 1 in c8, it would be
(9=2)r9c2 - (2=1)r9c7 - (1)r8c8 - (1)r5c8 - (1=9)r5c1
You would have 3 week links in a row, and you could not make the inference that either [r9c2]=9 or [r5c1]=9.
Said another way, (1)r8c8 = (1)r5c8 means there is a hard link between the two values. If [r8c8]=1, [r5c8]!=1 and vice versa. So <1> in [c8] is exhuasted, as (1=1)r58c8 states.
| daj95376 wrote: | I would have accepted:
Transport linkage: (1)r8c8=r5c8 - (1=9)r5c1
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I believe that is syntactically equivalent to (1)r58c8 - (1=9)r5c1.
I change it to (1=1)r58c8 to make the hard link more visible. |
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daj95376
Joined: 23 Aug 2008
Posts: 3854
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| Posted: Tue Apr 14, 2009 11:34 pm Post subject: |
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| gindaani wrote: | | daj95376 wrote: | I would have accepted:
Transport linkage: (1)r8c8=r5c8 - (1=9)r5c1
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I believe that is syntactically equivalent to (1)r58c8 - (1=9)r5c1.
I change it to (1=1)r58c8 to make the hard link more visible. |
There is a link/inference between candidates in cells:
e.g., (1=9)r5c5 -or- (4-5)r9c9
There is a link/inference between cells for a candidate:
e.g., (1)r1c8 = (1)r7c8 -or- (3)r3c4 - (3)r1c5 -- abbreviated as (1)r1c8=r7c8 and (3)r3c4-r1c5
If you wish to think that (1=1)r58c8 represents a strong link for <1> in [c8], then be my guest. It would have been nice if you had at least listed the row values in the same order as you intended the linkage to be interpreted; i.e., (1=1)r85c8.
Last edited by daj95376 on Tue Apr 14, 2009 11:41 pm; edited 1 time in total |
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storm_norm
Joined: 18 Oct 2007
Posts: 1741
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| Posted: Tue Apr 14, 2009 11:37 pm Post subject: |
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I like gindaani's move.
but the way he has described it doesn't "look" like a pincer transport.
the xy-wing pincers are the candidate 9. You can still extend the 9 in r8c8 to make the eliminations instead of jumping on the 1's in the middle of the xy-wing.
xy-wing in green
(9=2)r9c2 - (2=1)r9c7 - (1=9)r8c8 - (9=2)r7c9 - (2)r46c9 = (2-1)r6c7 = (1)r5c8 - (1=9)r5c1; r7c1 and r46c2 <> 9
this isn't your everyday transport...
in picture form...
the xy-wing is in the boxes |
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keith
Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
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| Posted: Tue Apr 14, 2009 11:45 pm Post subject: |
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| daj95376 wrote: | | gindaani wrote: | Sudopedia says "When groups of cells are used in the chain, they are named in the most efficient way." They go on to show that if all candidates are in one column, you can combine them. So (1)r8c8 = (1)r5c8 can be (1)r58c8. I personally prefer to combine the row column specification, but leave the hard link explicit, therefore (1=1)r58c8.
So, both notations are correct and differ only in their succinctness. |
I had to read the Sudopedia link several times in order to make sense of it. I finally decided that they left out a few words and used incomplete examples.
----- ----- ----- ----- my proposal for Sudopedia examples
When groups of cells are used in the chain, they are named in the most efficient way.
All cells in the group belong to a single row:
(1)r5c456 = (1)r5c9
All cells in the group belong to a single column:
(1)r45c4 = (1)r9c4
Unordered group, in a box: (not sure how to use this segment)
(1)r5c1 - (1)r5c4|r6c45 - (1)r6c9
-or-
(1)r5c1 - (1)r5c4=r6c45 - (1)r6c9
----- ----- ----- -----
Except for the example in a box, the group of cells does not exhaust the candidate in all of the cells of a house/unit.
Your (1=1)r58c8 exhausts <1> in [c8] ... and that's why I had a problem with it.
I would have accepted:
Transport linkage: (1)r8c8=r5c8 - (1=9)r5c1 |
Danny!
Just go edit the Sudopedia article!
Keith |
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daj95376
Joined: 23 Aug 2008
Posts: 3854
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| Posted: Tue Apr 14, 2009 11:49 pm Post subject: |
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| storm_norm wrote: | I like gindaani's move.
but the way he has described it doesn't "look" like a pincer transport.
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I've spent so much time discussing the notation, that I forgot to mention that gindaani's chain is interesting!
I don't have a firm definition for transport, but my gut feeling about how it works doesn't apply to this chain. Anyone have an authoritative link for transport? |
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storm_norm
Joined: 18 Oct 2007
Posts: 1741
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| Posted: Wed Apr 15, 2009 12:03 am Post subject: |
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| gindaani wrote: | | Code: |
+-----------------+--------------------+----------------+
| 6 5 79 | 34789 479 2 | 39 78 1 |
| 79 8 4 | 3679 1 3679 | 369 2 5 |
| 2 1 3 | 6789 679 5 | 69 78 4 |
+-----------------+--------------------+----------------+
| 5 *239 8 | 1 2469 3469 | 7 39 269 |
| d19 7 1269 | 2369 5 369 | 4 c139 8 |
| 4 *239 1269 | 23679 2679 8 | 12 5 269 |
+-----------------+--------------------+----------------+
| *179 4 1279 | 5 3 179 | 8 6 29 |
| 8 6 1279 | 2479 2479 1479 | 5 b19 3 |
| 3 e29 5 | 269 8 169 | a12 4 7 |
+-----------------+--------------------+----------------+
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The strong link on 1 at b and c provides the transport.
If a=1, b != 1, c=1, d=9
If a=2, e=9
Cells marked * can see both d and e cannot be 9 |
Danny,
that is a "mixed" w-wing.
gindaani used the strong inference on 1's to "see" the 1,9 cell at r5c1 and the 1,2 cell at r9c7 !!!
see it now?
the true pincer transport isn't really there unless you follow a path like the one shown in my pic.
gindaani, still a nice move. |
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daj95376
Joined: 23 Aug 2008
Posts: 3854
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| Posted: Wed Apr 15, 2009 12:25 am Post subject: |
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| keith wrote: | Danny!
Just go edit the Sudopedia article!
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I don't do HTML. |
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