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		| keith 
 
 
 Joined: 19 Sep 2005
 Posts: 3355
 Location: near Detroit, Michigan, USA
 
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				|  Posted: Tue Feb 26, 2013 4:25 pm    Post subject: Impossible Menneske No. 01 |   |  
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				| You asked for it!  I have not tried this one. 
 
  	  | Code: |  	  | M6901676 Impossible (3248) +-------+-------+-------+
 | . . . | . . 1 | . . . |
 | 7 2 . | . 9 . | 6 . . |
 | . . . | 2 . 5 | 9 . . |
 +-------+-------+-------+
 | 2 . . | . . . | . . . |
 | . 6 3 | 9 . . | 5 . . |
 | . . . | . . . | . 8 4 |
 +-------+-------+-------+
 | 8 . 2 | 4 . . | . . . |
 | 1 . 4 | . . 7 | . . 5 |
 | . . . | 5 . . | . . . |
 +-------+-------+-------+
 
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 Play this puzzle online at the Daily Sudoku site
 
 Keith
 
 Last edited by keith on Sun Mar 17, 2013 4:29 am; edited 1 time in total
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		| Marty R. 
 
 
 Joined: 12 Feb 2006
 Posts: 5770
 Location: Rochester, NY, USA
 
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				|  Posted: Tue Feb 26, 2013 7:28 pm    Post subject: |   |  
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				| I'm giving up and accepting the adjective in the subject line, even though someone will probably prove it possible. |  | 
	
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		| oaxen 
 
 
 Joined: 10 Jul 2006
 Posts: 96
 
 
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				|  Posted: Wed Feb 27, 2013 9:31 am    Post subject: |   |  
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				| Thank you Keith. Now I will prepare a cup of tea and start the work
 Lars
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		| JC Van Hay 
 
 
 Joined: 13 Jun 2010
 Posts: 494
 Location: Charleroi, Belgium
 
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				|  Posted: Wed Feb 27, 2013 10:36 am    Post subject: |   |  
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				| Strongest digits : 4,5 whose X Chains are weakly coupled in r2c8 and r4c5. They enter the following loop :
 
 Loop[5] : 5r2c8=5r1c8-5r1c1=5r6c1-5r4c3=(5-4)r4c5=4r4c6-4r2c6=4r2c8 @ 	  | Code: |  	  | +----------------------+----------------------+---------------------+ | 369(5)  3489  689-5  | 3678  34678    1     | 2478  2347(5)  2378 |
 | 7       2     158    | 38    9        38(4) | 6     -13(45)  138  |
 | 36      1348  168    | 2     34678    5     | 9     1347     1378 |
 +----------------------+----------------------+---------------------+
 | 2       178   178(5) | 137   -37(45)  3(4)  | 37    69       69   |
 | 4       6     3      | 9     278      28    | 5     127      127  |
 | 9(5)    179   179-5  | 1367  23567    236   | 237   8        4    |
 +----------------------+----------------------+---------------------+
 | 8       5     2      | 4     136      369   | 17    3679     3679 |
 | 1       39    4      | 368   2368     7     | 28    2369     5    |
 | 369     379   679    | 5     1238     2389  | 1248  2349     2389 |
 +----------------------+----------------------+---------------------+
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 :=> -5r16c3,r4c5=45=r2c8
 
 The solution of the loop solves the puzzle :
 
 Chain[11] : 5r4c5=(5-23)r6c5=[(34)r6c4.r4c6 ... 	  | Code: |  	  | +------------------+------------------------+--------------------+ | 3569  3489  5689 | 3678    34678    1     | 2478   23457  2378 |
 | 7     2     158  | 38      9        348   | 6      1345   138  |
 | 36    1348  168  | 2       34678    5     | 9      1347   1378 |
 +------------------+------------------------+--------------------+
 | 2     178   1578 | 137     7-34(5)  (34)  | (37)   69     69   |
 | 4     6     3    | 9       278      28    | 5      127    127  |
 | 59    179   1579 | 167(3)  67(235)  (236) | 7(23)  8      4    |
 +------------------+------------------------+--------------------+
 | 8     5     2    | 4       (136)    39(6) | (17)   3679   3679 |
 | 1     39    4    | (368)   (2368)   7     | (28)   2369   5    |
 | 369   379   679  | 5       1238     2389  | 1248   2349   2389 |
 +------------------+------------------------+--------------------+
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 ... or HP(23-6)r6c67=6#r7c6-(6=238)r8c457-(36#=1)r7c5-(1=7)r7c7-(7=34)r4c67]
 :=> -34r4c5; 11 Singles; r89c8=2 :=> r8c7=8; ste
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		| oaxen 
 
 
 Joined: 10 Jul 2006
 Posts: 96
 
 
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				|  Posted: Wed Feb 27, 2013 1:23 pm    Post subject: |   |  
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				| I agree with JC van Hay. The problem is to find favourable bivalues. After examining "4" inC7 I found out R9C7 must be correct. The next step was to decide that "5" must be in R2C3 and after that it is pure basic. Interesting puzzle like all in Menneskes impossible are. Only stupid that his random idéa makes me to believe that weeks ago I have solved the same puzzle.
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		| keith 
 
 
 Joined: 19 Sep 2005
 Posts: 3355
 Location: near Detroit, Michigan, USA
 
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				|  Posted: Wed Feb 27, 2013 2:11 pm    Post subject: |   |  
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				|  	  | oaxen wrote: |  	  | I agree with JC van Hay. The problem is to find favourable bivalues. After examining "4" inC7 I found out R9C7 must be correct. The next step was to decide that "5" must be in R2C3 and after that it is pure basic. Interesting puzzle like all in Menneskes impossible are. Only stupid that his random idéa makes me to believe that weeks ago I have solved the same puzzle.
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 Well, there are millions of puzzles, it is unlikely you will get the same one twice.
 
 I was focusing on R4 and proving R4C6 is 4 for any value in R4C4.  Can't quite get there.
 
 Keith
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		| oaxen 
 
 
 Joined: 10 Jul 2006
 Posts: 96
 
 
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				|  Posted: Wed Feb 27, 2013 2:57 pm    Post subject: |   |  
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				| No so many unimpossibles. And all the other levels are not so interesting. |  | 
	
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		| DonM 
 
 
 Joined: 15 Sep 2009
 Posts: 51
 
 
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				|  Posted: Fri Mar 01, 2013 6:44 am    Post subject: |   |  
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				| Another view, albeit quick & dirty: 
 Post SSTS: ER 8.3
 
  	  | Code: |  	  | *--------------------------------------------------------------------* | 3569   3489   5689   | 3678   34678  1      | 2478   23457  2378   |
 | 7      2      158    | 38     9      348    | 6      1345   138    |
 | 36     1348   168    | 2      34678  5      | 9      1347   1378   |
 |----------------------+----------------------+----------------------|
 | 2      178    1578   | 137    3457   34     | 37     69     69     |
 | 4      6      3      | 9      278    28     | 5      127    127    |
 | 59     179    1579   | 1367   23567  236    | 237    8      4      |
 |----------------------+----------------------+----------------------|
 | 8      5      2      | 4      136    369    | 17     3679   3679   |
 | 1      39     4      | 368    2368   7      | 28     2369   5      |
 | 369    379    679    | 5      1238   2389   | 1248   2349   2389   |
 *--------------------------------------------------------------------*
 
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 1. (7=3)r4c7-(3=4)r4c6-r2c6=r2c8-r9c8=(4-1)r9c7=(1)r7c7 :=>r7c7=1
 2. Sue-de-coq: [(2368)r8c45, (28)r7c7, (36)r7c5] :=> r7c6<36> r4c5=5
 3. (5)r4c5=r4c3-r2c3=(5-4)r2c8=r2c6-(4=3)r6c6-r6c7=(3-2)r6c7=(5)r6c6 :=> r4c5=5
 lclste
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