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au tough 5/4/12

 
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arkietech



Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA

PostPosted: Sat May 05, 2012 5:56 am    Post subject: au tough 5/4/12 Reply with quote

Code:

 *-----------*
 |...|7..|...|
 |8..|...|.31|
 |16.|..2|4..|
 |---+---+---|
 |...|8..|2..|
 |3..|.5.|..6|
 |..4|..6|...|
 |---+---+---|
 |..9|2..|.53|
 |67.|...|..9|
 |...|..8|...|
 *-----------*

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SudoQ



Joined: 02 Aug 2011
Posts: 127

PostPosted: Sat May 05, 2012 12:57 pm    Post subject: Reply with quote

A controversial solution?
Code:
r3c3=5 -> r1c3=3 -> r9c2=35

/SudoQ
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arkietech



Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA

PostPosted: Sat May 05, 2012 1:38 pm    Post subject: Reply with quote

SudoQ wrote:
A controversial solution?
Code:
r3c3=5 -> r1c3=3 -> r9c2=35

/SudoQ

Wow! Very Happy
I get the same thing with a Sue de Cog
Code:

 *-----------------------------------------------------------------------------*
 | 59      3459   *35      | 7       134689  13459   | 569     689     2       |
 | 8       2459    27-5    | 4569    469     459     | 5679    3       1       |
 | 1       6       7-35    | 359     389     2       | 4       789     78      |
 |-------------------------+-------------------------+-------------------------|
 | 579     159     6       | 8       13479   13479   | 2       1479    457     |
 | 3       1289    128     | 149     5       1479    | 179     14789   6       |
 | 579     1589    4       | 19      2       6       | 3       1789    578     |
 |-------------------------+-------------------------+-------------------------|
 | 4      #18      9       | 2       167     17      | 1678    5       3       |
 | 6       7     #*1358    | 1345    134     1345    | 18      2       9       |
 | 2       35-1  #*135     | 13569   13679   8       | 167     1467    47      |
 *-----------------------------------------------------------------------------*
Sue de Cog (length 4 no extra digit)
X=r189c3{1538}
Y=r7c2,r89c3{1538}
=> r23c3<>35, r9c2<>1; stte

35 in r23c3 is outside of X
1 in r9c2 is outside of Y

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keith



Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA

PostPosted: Sat May 05, 2012 1:54 pm    Post subject: Reply with quote

After basics:
Code:
+----------------------+----------------------+----------------------+
| 59     3459   35     | 7      134689 13459  | 569    689    2      |
| 8      2459   257    | 4569   469    459    | 5679   3      1      |
| 1      6     @357    |@359    389    2      | 4      789    78     |
+----------------------+----------------------+----------------------+
| 579    159    6      | 8      13479  13479  | 2      1479   457    |
| 3      1289   128    | 149    5      1479   | 179    14789  6      |
| 579    1589   4      | 19     2      6      | 3      1789   578    |
+----------------------+----------------------+----------------------+
| 4      18     9      | 2      167    17     | 1678   5      3      |
| 6      7     #1358   |#1345   134   #1345   | 18     2      9      |
| 2      135    135    |13-569  13679  8      | 167    1467   47     |
+----------------------+----------------------+----------------------+

Finned X-wing (grouped skyscraper) takes out 5 in R9C4.
Code:
+----------------------+----------------------+----------------------+
| 59     3459  A35     | 7      134689 13459  | 569    689    2      |
| 8      2459  2-57    | 4569   469    459    | 5679   3      1      |
| 1      6     3-57    | 359    389    2      | 4      789    78     |
+----------------------+----------------------+----------------------+
| 579    159    6      | 8      13479  13479  | 2      1479   457    |
| 3      1289   128    | 149    5      1479   | 179    14789  6      |
| 579    1589   4      | 19     2      6      | 3      1789   578    |
+----------------------+----------------------+----------------------+
| 4      18     9      | 2      167    17     | 1678   5      3      |
| 6      7      138    | 1345   134    1345   | 18     2      9      |
| 2     B135   C135    | 1369   13679  8      | 167    1467   47     |
+----------------------+----------------------+----------------------+

M-wing: 3 in A forces 3 in B. AC are pincers on 5.

That solves the puzzle.

Keith
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SudoQ



Joined: 02 Aug 2011
Posts: 127

PostPosted: Sat May 05, 2012 3:11 pm    Post subject: Reply with quote

arkietech wrote:
Wow! Very Happy
I get the same thing with a Sue de Cog
Thanks!

Normally, a single candidate contradiction can be rewritten.
In this case, I couldn't do this.
r8c3 or r9c3 must be 3 or 5.

/SudoQ
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SudoQ



Joined: 02 Aug 2011
Posts: 127

PostPosted: Sat May 05, 2012 7:37 pm    Post subject: Reply with quote

Here is a solution that only requires singles before and after the step:

Code:
r7c2=x -> r5c3=x (x=1/8) => r5c3<>27
/SudoQ
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ronk



Joined: 07 May 2006
Posts: 398

PostPosted: Sun May 06, 2012 3:24 am    Post subject: Reply with quote

SudoQ wrote:
Here is a solution that only requires singles before and after the step:

r7c2=x -> r5c3=x (x=1/8 ) => r5c3<>27

Nice, you have used an m-ring (see Type C here).

In NL notation: r7c2 -1- r789c3 =1= r5c3 =8= r789c3 -8- r7c2 - continuous loop

In AIC notation: (8=1)r7c2 - (1)r789c3 = (1-8)r5c3 = (8)r789c3 - loop ==> r5c3=18
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tlanglet



Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills

PostPosted: Sun May 06, 2012 4:57 am    Post subject: Reply with quote

After failing to find any productive VH steps, I started looking for anp()s and immediately found an invalid condition.

anp(7=35)r13c3-(35=1=8)r98c3 which would mean that r7c2 is empty. Thus, r3c3=7

Ted
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aran



Joined: 19 Apr 2010
Posts: 70

PostPosted: Sun May 06, 2012 9:11 am    Post subject: Reply with quote

Arkietech
Always nice to see a Sue de Coq given its "historical" significance.
SdC being a specific instance of a more general form - Dual-Linked ALS...with the particularity that the specific form is more difficult to define than the general !
Here the general being :
A=3518r189c3
B=18r7c2
=>all the elims


Last edited by aran on Sun May 06, 2012 9:17 am; edited 1 time in total
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SudoQ



Joined: 02 Aug 2011
Posts: 127

PostPosted: Sun May 06, 2012 9:14 am    Post subject: Reply with quote

ronk wrote:
In NL notation: r7c2 -1- r789c3 =1= r5c3 =8= r789c3 -8- r7c2 - continuous loop
Hi Ronk!

Is it possible to write your NL notation like this:
r7c2 -1- r89c3 =1= r5c3 =8= r8c3 -8- r7c2 - continuous loop
(since r7c3<>18 and r9c3<>8)?

I don't understand the "continuous loop" part (but you don't need to try to explain it!).

When I look at your link, it seems that this M-wing is also of type D!?

Finally, do you have a suggestion how to write my first example
(r3c3=5 -> r1c3=3 -> r9c2=35) in a nicer way?

/SudoQ
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