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NOV 21 VH

 
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storm_norm



Joined: 18 Oct 2007
Posts: 1741

PostPosted: Wed Nov 21, 2007 6:12 am    Post subject: NOV 21 VH Reply with quote

basics get you to the grid below, minus the clutter.

I love the finns in this one. there are three at the same time.

the @ is a finned x-wing on 2, removing 2 from r7c2,3

the # is a finned on x-wing on 7, removing 7 from r5c6

the % is a finned x-wing on 8, removing 8 from r4c4

Code:
------------------------------------------------------------------------------|
| 3689%   1       3689    | 238     5       238%    | 7       4       69      |
| 29@     4       5       | 6       7       1       | 8       29@     3       |
| 7       26      38      | 4       38      9       | 16      5       126     |
------------------------------------------------------------------------------|
| 689%    3       689     | 17-8#   4       78#%    | 2       179#    5       |
| 5       279     289     | 12378   6       238-7%  | 134     179     1479    |
| 1       27      4       | 237     9       5       | 36      8       76      |
------------------------------------------------------------------------------|
| 2369@   69-2    1369-2  | 5       23      347#    | 14      127@#   8       |
| 4       5       12      | 78      28      6       | 9       3       127     |
| 23@     8       7       | 9       1       34      | 5       6       24      |
------------------------------------------------------------------------------|
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Johan



Joined: 25 Jun 2007
Posts: 206
Location: Bornem Belgium

PostPosted: Wed Nov 21, 2007 8:13 am    Post subject: Reply with quote

There are also two ER's for digit <2> present in the grid.

1. ER <2> in Box 9 eliminates <2> in R7C2

2. ER <2> in Box 1 eliminates <2> in R3C9

Or using the strong link on <2> in R9, which pins <2> in R2C8, that

solves the puzzle in one step.
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andras



Joined: 31 Oct 2007
Posts: 56
Location: Mid Wales

PostPosted: Wed Nov 21, 2007 9:35 am    Post subject: Reply with quote

Hmmm - two xy-wings did it for me. Smile

John
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cgordon



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

PostPosted: Wed Nov 21, 2007 3:57 pm    Post subject: Reply with quote

Actually I couldn't read Norm's grid - except for the singles - but I got more of those after the basics. But definitely can't see Johan's two ERs. Johan, you mention one Box for each ER - but you need 4 boxes for an ER - I just don't see any configurations on 2's that would provide any ERs. I've been wrong before though.

Did get 2 x-wings - as did Andras - but am struggling to finish off. This seems to be a hard one.


Last edited by cgordon on Wed Nov 21, 2007 6:49 pm; edited 1 time in total
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Marty R.



Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

PostPosted: Wed Nov 21, 2007 4:03 pm    Post subject: Reply with quote

One XY-Wing pivoted in r9c6 did it for me.
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Johan



Joined: 25 Jun 2007
Posts: 206
Location: Bornem Belgium

PostPosted: Wed Nov 21, 2007 6:17 pm    Post subject: Reply with quote

Quote:
But definitely can't see Johan's two ERs. Johan, you mention one Box for each ER - but you need 4 boxes for an ER - I just don't see any configurations on 2's that would provide any ERs. I've been wrong before though.


cg,

This is the ER in Box 9 for digit <2>, only using the <2>'s relevant for the ER.

* = strong link on <2> in R3
Code:

+-------+-------+-------+
| . . . | . . . | . . . |
| . . . | . . . | . . . |
| . *2. | . . . | . . *2|
+-------+-------+-------+
| . . . | . . . | . . . |
| . . . | . . . | . . . |
| . . . | . . . | . . . |
+-------+-------+-------+
| . -2 .| . .   | . 2 . |
| . . . | . . . |er er 2|
| . . . | . . . |er er 2|
+-------+-------+-------+


ER <2> in Box 1

* = strong link on <2> in R9

Code:

+-------+-------+-------+
| .er er| . . . | . . . |
|2 er er|.. . . | . . . |
| . 2 . | . . . | . . -2|
+-------+-------+-------+
| . . . | . . . | . . . |
| . . . | . . . | . . . |
| . . . | . . . | . . . |
+-------+-------+-------+
| .   . | . . . | .   . |
| . . . | . . . | . .   |
|*2 . . | . . . | . . *2|
+-------+-------+-------+
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cgordon



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

PostPosted: Wed Nov 21, 2007 6:48 pm    Post subject: Reply with quote

Johan: After my basic eliminations I still had a pile of candidate 2's. My understanding of the ER technique is that the hinge and target must be opposite a row or column containing ONLY two candidates - in your case R3 and R9. Maybe you got further than me with your basic elininations. Or are we talking about the same application of an ER?

Code:
            
+-------+-------+-------+   
| 2 . 2 | 2 . 2 | . . 2 |   
| 2 . . | . . . | . 2 . |   
| . 2 2 | . 2 . | . . 2 |   
+-------+-------+-------+   
| . . . | . . . | . . . |   
| . 2 2 | 2 . 2 | . . . |   
| . 2 . | 2 . . | . . . |   
+-------+-------+-------+   
| 2 2 2 | . 2 2 | . 2 . |   
| . . 2 | 2 2 . | . . 2 |   
| 2 . . | . . 2 | . . 2 |
+-------+-------+-------+
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Johan



Joined: 25 Jun 2007
Posts: 206
Location: Bornem Belgium

PostPosted: Wed Nov 21, 2007 7:18 pm    Post subject: Reply with quote

Quote:
Maybe you got further than me with your basic elininations.


cg,

This is my grid after basics :
Code:

+----------------+---------------+--------------+
| 3689 1   3689  | 238   5  238  | 7   4   69   |
| 29   4   5     | 6     7  1    | 8   29  3    |
| 7    26  38    | 4     38 9    | 16  5   126  |
+----------------+---------------+--------------+
| 689  3   689   | 178   4  78   | 2   179 5    |
| 5    279 289   | 12378 6  2378 | 134 179 1479 |
| 1    27  4     | 237   9  5    | 36  8   67   |
+----------------+---------------+--------------+
| 2369 269 12369 | 5     23 347  | 14  127 8    |
| 4    5   12    | 78    28 6    | 9   3   127  |
| 23   8   7     | 9     1  34   | 5   6   24   |
+----------------+---------------+--------------+
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duffy



Joined: 13 Sep 2007
Posts: 26
Location: Toronto Canada

PostPosted: Wed Nov 21, 2007 8:48 pm    Post subject: Reply with quote

Lots of interesting observations based on the two grids shown (by storm_norm and Johan), which are the same. Shocked
Marty probably found that the solution fell out easily after the 2 in r7c8 was eliminated by the xy-wing he spotted. I did not see that wing for myself, but used even a different step from those already noted: I removed the same 2 based on the skyscraper on 2's in r2 and r9. And a hint for cgordon: cut back on the 2's (to get to Johan's grid) by noting the naked triple / hidden pair that are shown in r3. Wink
Don D.
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cgordon



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

PostPosted: Wed Nov 21, 2007 8:55 pm    Post subject: Reply with quote

Johan: I missed some basic <2> elimininations in Box 1 - but I probably still wouldn't have spotted the upside-down, turned-about L shaped hinge in Box 9. Well done!

As for the other one, I can't get rid of my 2 in R9C6.
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duffy



Joined: 13 Sep 2007
Posts: 26
Location: Toronto Canada

PostPosted: Wed Nov 21, 2007 9:34 pm    Post subject: Reply with quote

Hi cgordon,
My hint above leads to all '2' candidates in c5, being in box8: that will clear out the one you are interested in. Laughing
Don.
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DennyOR



Joined: 12 Sep 2007
Posts: 33
Location: Portland, Oregon

PostPosted: Fri Nov 23, 2007 6:08 am    Post subject: Reply with quote

From Johan's position, the XY chain 24-41-16-62 did it for me.
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