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Menneske impossible

 
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ffred



Joined: 29 Oct 2012
Posts: 19
Location: Kent, Egland
PostPosted: Tue Oct 30, 2012 9:14 am    Post subject: Menneske impossible Reply with quote
Hi. I introduced myself in the theory forum & said that I'd post a few Menneskes. Before going on a short trip I ran off some post-basic sheets of Menneske 'impossibles', and here's one. I can't give you the number or the starting grid, but as far as I remember there are no solved squares.
Code:

+------------------+--------------------+------------------+
| 267  25678  2358 | 369   67     1     | 4     35679 567  |
| 467  4567   345  | 3469  8      2     | 1     35679 567  |
| 9    1      34   | 5     467    3467  | 8     367   2    |
+------------------+--------------------+------------------+
| 247  2478   248  | 12468 124567 45678 | 9     25678 3    |
| 5    9      1    | 2368  267    3678  | 267   2678  4    |
| 2347 23478  6    | 248   9      4578  | 257   1     578  |
+------------------+--------------------+------------------+
| 8    23456  9    | 1246  12456  456   | 23567 2567  1567 |
| 1    2456   245  | 7     3      4568  | 256   2568  9    |
| 236  2356   7    | 1268  1256   9     | 2356  4     1568 |
+------------------+--------------------+------------------+

Play this puzzle online at the Daily Sudoku site


Hope you like it, Fred
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aran



Joined: 19 Apr 2010
Posts: 70
PostPosted: Tue Oct 30, 2012 2:36 pm    Post subject: Reply with quote
Code:
*-----------------------------------------------------------------------------*
 | 2367    235678  2358    | 369     67      1       | 4       35679   567     |
 | 3467    34567   345     | 3469    8       2       | 1       35679   567     |
 | 9       1       34      | 5       467     3467    | 8       367     2       |
 |-------------------------+-------------------------+-------------------------|
 | 247     2478    248     | 12468   124567  45678   | 9       25678   3       |
 | 5       9       1       | 2368    267     3678    | 267     2678    4       |
 | 2347    23478   6       | 2348    9       34578   | 257     1       578     |
 |-------------------------+-------------------------+-------------------------|
 | 8       23456   9       | 1246    12456   456     | 23567   23567   1567    |
 | 1       2456    245     | 7       3       4568    | 256     2568    9       |
 | 236     2356    7       | 1268    1256    9       | 2356    4       1568    |
 *-----------------------------------------------------------------------------*
(4=3)r3c3-3r12c123=(AUR-UR)39r12c48=sis{567r12c8 ; 4r2c4 ; 6r12c4}
567r12c8=>QNT567r12c89-(67=3)r3c8 -(3=4)r3c3
4r2c4-r2c123=4r3c3
6r12c4-(6=7)r1c5-(67=34)r3c56-34r3c3 : impossible
: =>r3c3=4 ste
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JC Van Hay



Joined: 13 Jun 2010
Posts: 494
Location: Charleroi, Belgium
PostPosted: Tue Oct 30, 2012 3:04 pm    Post subject: Reply with quote
Hmmm ....

(4=3)r3c3-3r12c"12"3=DP(39)r12c48 :=> -3r3c3; LC and Singles to the end
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daj95376



Joined: 23 Aug 2008
Posts: 3854
PostPosted: Tue Oct 30, 2012 4:02 pm    Post subject: Reply with quote
Impossible it ain't.

Code:
 +--------------------------------------------------------------------------------+
 |  267     25678   2358    |  369     67      1       |  4       35679   567     |
 |  467     4567    345     |  3469    8       2       |  1       35679   567     |
 |  9       1       34      |  5       467     3467    |  8       367     2       |
 |--------------------------+--------------------------+--------------------------|
 |  247     2478    248     |  12468   124567  45678   |  9       25678   3       |
 |  5       9       1       |  2368    267     3678    |  267     2678    4       |
 |  2347    23478   6       |  248     9       4578    |  257     1       578     |
 |--------------------------+--------------------------+--------------------------|
 |  8       23456   9       |  1246    12456   456     |  23567   2567    1567    |
 |  1       2456    245     |  7       3       4568    |  256     2568    9       |
 |  236     2356    7       |  1268    1256    9       |  2356    4       1568    |
 +--------------------------------------------------------------------------------+
 # 148 eliminations remain

 M-Ring  C (6=7)r1c5 - r3c56 = (7-6)r3c8 = (6)r3c56 - loop  =>  r3c8<>3; r12c4<>6

 r12c48  <39> UR Type 1.2223             <> 39   r2c4
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Marty R.



Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
PostPosted: Tue Oct 30, 2012 6:25 pm    Post subject: Reply with quote
daj95376 wrote:
Impossible it ain't.

Code:
 +--------------------------------------------------------------------------------+
 |  267     25678   2358    |  369     67      1       |  4       35679   567     |
 |  467     4567    345     |  3469    8       2       |  1       35679   567     |
 |  9       1       34      |  5       467     3467    |  8       367     2       |
 |--------------------------+--------------------------+--------------------------|
 |  247     2478    248     |  12468   124567  45678   |  9       25678   3       |
 |  5       9       1       |  2368    267     3678    |  267     2678    4       |
 |  2347    23478   6       |  248     9       4578    |  257     1       578     |
 |--------------------------+--------------------------+--------------------------|
 |  8       23456   9       |  1246    12456   456     |  23567   2567    1567    |
 |  1       2456    245     |  7       3       4568    |  256     2568    9       |
 |  236     2356    7       |  1268    1256    9       |  2356    4       1568    |
 +--------------------------------------------------------------------------------+
 # 148 eliminations remain

 M-Ring  C (6=7)r1c5 - r3c56 = (7-6)r3c8 = (6)r3c56 - loop  =>  r3c8<>3; r12c4<>6

 r12c48  <39> UR Type 1.2223             <> 39   r2c4


Danny,

You mentioned in another thread that a characteristic of an M-Ring is having pincers in the same house, box 2 in this case. What is the loop in your notation and what allows the elimination of the 3?
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arkietech



Joined: 31 Jul 2008
Posts: 1834
Location: Northwest Arkansas USA
PostPosted: Tue Oct 30, 2012 6:50 pm    Post subject: Reply with quote
daj95376 wrote:
Impossible it ain't.

Code:
 +--------------------------------------------------------------------------------+
 |  267     25678   2358    |  369     67      1       |  4       35679   567     |
 |  467     4567    345     |  3469    8       2       |  1       35679   567     |
 |  9       1       34      |  5       467     3467    |  8       367     2       |
 |--------------------------+--------------------------+--------------------------|
 |  247     2478    248     |  12468   124567  45678   |  9       25678   3       |
 |  5       9       1       |  2368    267     3678    |  267     2678    4       |
 |  2347    23478   6       |  248     9       4578    |  257     1       578     |
 |--------------------------+--------------------------+--------------------------|
 |  8       23456   9       |  1246    12456   456     |  23567   2567    1567    |
 |  1       2456    245     |  7       3       4568    |  256     2568    9       |
 |  236     2356    7       |  1268    1256    9       |  2356    4       1568    |
 +--------------------------------------------------------------------------------+
 # 148 eliminations remain

 M-Ring  C (6=7)r1c5 - r3c56 = (7-6)r3c8 = (6)r3c56 - loop  =>  r3c8<>3; r12c4<>6

 r12c48  <39> UR Type 1.2223             <> 39   r2c4


Wow! Very Happy

I missed the ring or loop completely. There is a Sue de Cog with the same eliminations. I have got to revisit loops.
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ffred



Joined: 29 Oct 2012
Posts: 19
Location: Kent, Egland
PostPosted: Tue Oct 30, 2012 8:33 pm    Post subject: Reply with quote
You guys are fast workers!

I used the ALS pair A = (6,7)r1c5 , B = (3,4,6,7) r3c356, doubly linked by 6 & 7. r3c8 <>3, r12c4 <> 6. Followed by a UR type 1: r2c4 = 4.

I'll study your answers!

Fred
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keith



Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
PostPosted: Tue Oct 30, 2012 9:17 pm    Post subject: Reply with quote
Marty R. wrote:
daj95376 wrote:
Impossible it ain't.

Code:
 +--------------------------------------------------------------------------------+
 |  267     25678   2358    |  369    A67      1       |  4       35679   567     |
 |  467     4567    345     |  3469    8       2       |  1       35679   567     |
 |  9       1       34      |  5      B467    B3467    |  8      C367     2       |
 |--------------------------+--------------------------+--------------------------|
 |  247     2478    248     |  12468   124567  45678   |  9       25678   3       |
 |  5       9       1       |  2368    267     3678    |  267     2678    4       |
 |  2347    23478   6       |  248     9       4578    |  257     1       578     |
 |--------------------------+--------------------------+--------------------------|
 |  8       23456   9       |  1246    12456   456     |  23567   2567    1567    |
 |  1       2456    245     |  7       3       4568    |  256     2568    9       |
 |  236     2356    7       |  1268    1256    9       |  2356    4       1568    |
 +--------------------------------------------------------------------------------+
 # 148 eliminations remain

 M-Ring  C (6=7)r1c5 - r3c56 = (7-6)r3c8 = (6)r3c56 - loop  =>  r3c8<>3; r12c4<>6

 r12c48  <39> UR Type 1.2223             <> 39   r2c4


Danny,

You mentioned in another thread that a characteristic of an M-Ring is having pincers in the same house, box 2 in this case. What is the loop in your notation and what allows the elimination of the 3?


Marty, the elimination C<>3 is certainly correct but, like you, I do not see how it follows from the M-ring.

Note that if A is 6, C is 6, if A is 7, C is 7. C cannot be 3. It's a Sue de Coq kind of move.

Keith
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daj95376



Joined: 23 Aug 2008
Posts: 3854
PostPosted: Tue Oct 30, 2012 10:34 pm    Post subject: Reply with quote
Marty R. wrote:
daj95376 wrote:
Code:
  M-Ring  C (6=7)r1c5 - r3c56 = (7-6)r3c8 = (6)r3c56 - loop  =>  r3c8<>3; r12c4<>6

 r12c48  <39> UR Type 1.2223             <> 39   r2c4

You mentioned in another thread that a characteristic of an M-Ring is having pincers in the same house, box 2 in this case. What is the loop in your notation and what allows the elimination of the 3?

There is a weak link in r3c8 between <7> and <6>. When there is a loop/ring present, this translates into eliminating all other candidates in r3c8.

M-Ring C (6=7)r1c5 - r3c56 = (7-6)r3c8 = (6)r3c56 - loop => r3c8<>3; r12c4<>6

M-Ring Translation: left-to-right

r1c5<>6; r1c5=7; r3c56<>7; r3c8=7; r3c8<>6; r3c56=6; (loop) r1c5<>6

M-Ring Translation: right-to-left

r1c5=6; r3c56<>6; r3c8=6; r3c8<>7; r3c56=7; r1c5<>7; (loop) r1c5=6

No matter whether you assume r1c5<>6 or you assume r1c5=6, the loop only allows for r3c8=7 or r3c8=6. All other candidates can be eliminated in r3c8.

Regards, Danny
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tlanglet



Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills
PostPosted: Wed Oct 31, 2012 1:33 pm    Post subject: Reply with quote
I also found the AUR(39)r12c49 SIS=3r3c68 => r3c3<>3

Ted
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