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Franken Swordfish.

 
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wapati



Joined: 10 Jun 2008
Posts: 472
Location: Brampton, Ontario, Canada.
PostPosted: Tue Apr 28, 2009 2:04 pm    Post subject: Franken Swordfish. Reply with quote
I am taking a look at "Franken" 'cause it seems interesting.

This puzzle, that I would have a lot of trouble with, comes down to a pretty easy Franken Sword and a finned sword.

Code:
6 . .|5 . .|3 . .
. 3 .|. . .|. . 6
1 7 9|. 3 .|. 4 .
-----+-----+-----
. 2 7|9 . .|. . .
. . .|. 8 .|. . .
. . .|. . 4|6 9 .
-----+-----+-----
. 8 .|. 9 .|4 1 3
3 . .|. . .|. 6 .
. . 6|. . 1|. . 7
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storm_norm



Joined: 18 Oct 2007
Posts: 1741
PostPosted: Tue Apr 28, 2009 7:33 pm    Post subject: Reply with quote
I have been trying to incorporate als in my chains in the more difficult puzzles and this puzzle has given me some practice.
in the following grid is a hidden pair ALS that can be exploited.
notice that if the 2 in I is false, then the hidden pair {2,7} in GH is true.
and vice versa.
then if the hidden pair is true, then the 5 in H is false.
Code:
.---------------------.---------------------.---------------------.
| 6      4      28    | 5      127    2789  | 3      278    19    |
|A25     3      258   | 12478  1247   2789  | 19     278    6     |
| 1      7      9     | 268    3      268   | 258    4      258   |
:---------------------+---------------------+---------------------:
| 458    2      7     | 9      6     E35    | 158    358    1458  |
| 9      6      14    | 12     8     F235   | 7      235    245   |
|J-58    15     3     |G127   H1257   4     | 6      9     I258   |
:---------------------+---------------------+---------------------:
| 7      8     C25    | 26     9     D256   | 4      1      3     |
| 3      159    14    | 2478   2457   2578  | 259    6      259   |
|B245    59     6     | 3      245    1     | 2589   258    7     |
'---------------------'---------------------'---------------------'

this longish chain can be formed
(5=2)A - (2)B = (2-5)C = (5)D - (5)EF = (5)H - hp(27)GH = (2-8)I = (8)J; J is not 5

with the 8 placed in r6c1 a cycle on 5's is there.
(5)...r6c2 = r4c1 - r2c1 = r2c3 - r7c3 = r7c6 - r45c6 = r6c5; r6c9 and r9c1 is not 5.
this is either the finned sword or the kraken sword??? not sure.

then the x-wing overlay on the 3's in the UR {3,5} in r45c68 means that the other 5's in col 6 and 8 have a strong inference on them since they can't all be false.
Code:
.---------------------.---------------------.---------------------.
| 6      4      28    | 5      127    2789  | 3      278    19    |
| 25     3      258   | 12478  1247   2789  | 19     278    6     |
| 1      7      9     | 268    3      268   | 258    4      58    |
:---------------------+---------------------+---------------------:
| 45     2      7     | 9      6     U35    | 158   U358    1458  |
| 9      6      14    | 12     8     U235   | 7     U35     45    |
| 8      15     3     | 17     157    4     | 6      9      2     |
:---------------------+---------------------+---------------------:
| 7      8      25    | 26     9     B256   | 4      1      3     |
| 3      159    14    | 2478   2457  C2578  | 259    6      59    |
| 24     59     6     | 3    D24-5    1     | 2589  A258    7     |
'---------------------'---------------------'---------------------'

UR35[(5)A = (5)BC]; D is not 5 and solves the puzzle.
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wapati



Joined: 10 Jun 2008
Posts: 472
Location: Brampton, Ontario, Canada.
PostPosted: Thu Apr 30, 2009 2:25 pm    Post subject: Reply with quote
storm_norm wrote:


with the 8 placed in r6c1 a cycle on 5's is there.
(5)...r6c2 = r4c1 - r2c1 = r2c3 - r7c3 = r7c6 - r45c6 = r6c5; r6c9 and r9c1 is not 5.
this is either the finned sword or the kraken sword??? not sure.

The franken sword is visible as the first interesting step.

Code:
.----------------.-------------------.-----------------.
| 6     4    28  | 5      127   2789 | 3     278  19   |
| 25    3    258 | 12478  1247  2789 | 19    278  6    |
| 1     7    9   | 268    3     268  | 258   4    258  |
:----------------+-------------------+-----------------:
| 458   2    7   | 9      6     35   | 158   358  1458 |
| 9     6    14  | 12     8     235  | 7     235  245  |
| 8-5  #15   3   | 127   #1257  4    | 6     9    28-5 |
:----------------+-------------------+-----------------:
| 7     8    25  | 26     9     256  | 4     1    3    |
| 3    #159  14  | 2478  #2457  278-5|@259   6   @259  |
| 24-5 #59   6   | 3     #245   1    |@2589 @258  7    |
'----------------'-------------------'-----------------'


The cells marked "@" are the interesting bits and only act horizontally, in this case.

Norm, you do deep stuff in my books!
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