February 19, 2017

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February 19, 2017

Postby ArkieTech » Sun Feb 19, 2017 12:14 am

Code: Select all
 *-----------*
 |...|...|6..|
 |.57|.9.|...|
 |.14|7.6|..3|
 |---+---+---|
 |...|.4.|51.|
 |1..|...|..2|
 |.3.|.1.|...|
 |---+---+---|
 |2..|9.8|.3.|
 |...|.6.|8..|
 |..6|...|.7.|
 *-----------*


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Re: February 19, 2017

Postby Leren » Sun Feb 19, 2017 12:24 am

Code: Select all
*--------------------------------------------------------------*
|b39    29    239    | 1458  58    145    | 6     48    7      |
| 6     5     7      | 348   9     34     | 124   248   148    |
| 8     1     4      | 7     2     6      | 9     5     3      |
|--------------------+--------------------+--------------------|
|b79    2679  289    | 2368  4     2379   | 5     1     89     |
| 1     4679  589    | 568   578   579    | 3     4689  2      |
| 459   3     2589   | 2568  1     259    | 7     4689  489    |
|--------------------+--------------------+--------------------|
| 2    a47    1-5    | 9    a57    8      | 14    3     6      |
|b34579 479   1359   | 1245  6     12457  | 8     249   1459   |
|b459   8     6      | 1245  3     1245   | 124   7     1459   |
*--------------------------------------------------------------*

ALS XZ Rule: X = 4, Z = 5: (5=4) r7c25 - (4=5) r1489c1 => - 5 r7c3; stte

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Re: February 19, 2017

Postby SteveG48 » Sun Feb 19, 2017 1:11 am

Code: Select all
 *--------------------------------------------------------------------*
 |b39     29     239    | 1458   58     145    | 6      48     7      |
 | 6      5      7      | 348    9      34     | 124    248    148    |
 | 8      1      4      | 7      2      6      | 9      5      3      |
 *----------------------+----------------------+----------------------|
 |b79     2679   289    | 2368   4      2379   | 5      1      89     |
 | 1      4679   589    | 568    578    579    | 3      4689   2      |
 | 459    3      2589   | 2568   1      259    | 7      4689   489    |
 *----------------------+----------------------+----------------------|
 | 2      7-4   a15     | 9      57     8      |a14     3      6      |
 |b34579  479    1359   | 1245   6      12457  | 8      249    1459   |
 |b459    8      6      | 1245   3      1245   | 124    7      1459   |
 *--------------------------------------------------------------------*


Essentially the same:

(4=15)r7c37 - (5=3479)r1489c1 => -4 r7c2 ; stte
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Re: February 19, 2017

Postby Cenoman » Sun Feb 19, 2017 9:04 am

Code: Select all
 +-----------------------+----------------------+---------------------+
 | 39      29     239    | 1458  e58    145     | 6    e48     7      |
 | 6       5      7      | 348    9     34      | 124   248    148    |
 | 8       1      4      | 7      2     6       | 9     5      3      |
 +-----------------------+----------------------+---------------------+
 | 79      2679   289    | 2368   4     2379    | 5     1      89     |
 | 1      g4679   589    | 568    578   579     | 3    f4689   2      |
 |a59-4    3      2589   | 2568   1     259     | 7     4689   489    |
 +-----------------------+----------------------+---------------------+
 | 2       47    c15     | 9     d57    8       | 14    3      6      |
 |b34579   479    1359   | 1245   6     12457   | 8     249    1459   |
 |b459     8      6      | 1245   3     1245    | 124   7      1459   |
 +-----------------------+----------------------+---------------------+

(5)r6c1 = r89c1 - r7c3 = r7c5 - (5=4)r1c58 - r5c8 = (4)r5c2 => -4 r6c1; stte

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Re: February 19, 2017

Postby bat999 » Sun Feb 19, 2017 11:51 am

Code: Select all
.----------------------.-------------------.------------------.
|  39      29     239  | 1458  a58   145   | 6    a48     7   |
|  6       5      7    | 348    9    34    | 124  248    148  |
|  8       1      4    | 7      2    6     | 9    5      3    |
:----------------------+-------------------+------------------:
| d79     d2679  d289  | 2368   4    2379  | 5    1      89   |
|  1      d4679  d589  | 568    578  579   | 3    689-4  2    |
|  459     3     d2589 | 2568   1    259   | 7    4689   489  |
:----------------------+-------------------+------------------:
|  2       47    c15   | 9     b57   8     | 14   3      6    |
|  34579   479    1359 | 1245   6    12457 | 8    249    1459 |
|  459     8      6    | 1245   3    1245  | 124  7      1459 |
'----------------------'-------------------'------------------'
(4=5)r1c58 - r7c5 = r7c3 - (5=4)r4c123,r5c23,r6c3 => -4 r5c8; stte
8-)
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Re: February 19, 2017

Postby Leren » Sun Feb 19, 2017 7:53 pm

bat999 wrote : (4=5)r1c58 - r7c5 = r7c3 - (5=4)r4c123,r5c23,r6c3

When a large ALS occupies all but one of the unsolved cells in its house there is usually a simpler interpretation.

In this case you could write (4=5)r1c58 - r7c5 = r7c3 - r56c3 = (5-4) r6c1 = (4) r5c2. This uses 3 fewer cells at the end and only two digits are involved in the whole chain.

Hope this helps, Leren
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Re: February 19, 2017

Postby Ngisa » Sun Feb 19, 2017 8:22 pm

Code: Select all
+-----------------+----------------+---------------+
| f39    29   239  | 145  k58  145   | 6   l48   7    |
| 6     5    7    | 348  9   34    | 124 248  148  |
| 8     1    4    | 7    2   6     | 9   5    3    |
+-----------------+----------------+---------------+
| 79    2679 289  | 2368 4   2379  | 5   1    a89   |
| 1     n4679 589  | 568  578 579   | 3   m4689 2    |
| 59-4   3    2589 | 2568 1   259   | 7   4689 a489  |
+-----------------+----------------+---------------+
| 2     47   i15   | 9    j57  8     | 14  3    6    |
| dg34579 d479  dh1359 | 1245 6   12457 | 8   c249  b1459 |
| e459   8    6    | 1245 3   1245  | 124 7    b1459 |
+-----------------+----------------+---------------+

(4=89)r46c9 - r89c9 = r8c8 - r8c123 = r9c1 - (9=3)r1c1 - r8c1 = (3-1)r8c3 = (1-5)r7c3 = r7c5 -(5=8)r1c5 - (8=4)r1c8 - r5c8 = (4)r5c2 => -4 r6c1; stte

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Re: February 19, 2017

Postby bat999 » Sun Feb 19, 2017 9:46 pm

Leren wrote:... there is usually a simpler interpretation...

No, I prefer to minimize the quantity of "nodes" in my notation.
Mine has 4 nodes a,b,c,d.
(4=5)r1c58 - r7c5 = r7c3 - (5=4)r4c123,r5c23,r6c3

Yours has 6 nodes a,b,c,d,e,f.
(4=5)r1c58 - r7c5 = r7c3 - r56c3 = (5-4)r6c1 = (4)r5c2
8-)
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Re: February 19, 2017

Postby Sudtyro2 » Mon Feb 20, 2017 2:55 pm

bat999 wrote: Mine has 4 nodes a,b,c,d.
(4=5)r1c58 - r7c5 = r7c3 - (5=4)r4c123,r5c23,r6c3
Yours has 6 nodes a,b,c,d,e,f.
(4=5)r1c58 - r7c5 = r7c3 - r56c3 = (5-4)r6c1 = (4)r5c2

Just like in the October 3, 2016 puzzle discussion, IMHO, I'd call it a tie if one uses (nodes + cells) as the metric. In this case it's 14 for either solution.

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Re: February 19, 2017

Postby bat999 » Mon Feb 20, 2017 3:34 pm

Sudtyro2 wrote:... call it a tie...
It's not a contest, it's my preference. :D
My road trip from (4=5)r1c58... to ... (5=4)r4c123,r5c23,r6c3 has only two toilet breaks (at r7c5 and r7c3). ;)
8-)
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Re: February 19, 2017

Postby SteveG48 » Mon Feb 20, 2017 4:35 pm

bat999 wrote:It's not a contest, it's my preference. :D


And that's reason enough, of course, but let's not forget the lesson that Leren is teaching. Any time an elimination results in an ALS that includes all but one cell in the group, then it's guaranteed that you've also created a hidden single in the remaining cell. That can be useful. Whether you use it, of course, will vary from case to case.
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Re: February 19, 2017

Postby pjb » Mon Feb 20, 2017 9:09 pm

Code: Select all
 39      29      239    | 1458   58     145    | 6      48     7     
 6       5       7      | 348    9      34     | 124    248    148   
 8       1       4      | 7      2      6      | 9      5      3     
------------------------+----------------------+---------------------
 79      2679    289    | 2368   4      2379   | 5      1      89     
 1      e4679   c589    | 568    578    579    | 3      4689   2     
d459     3      c2589   | 2568   1      259    | 7      4689   489   
------------------------+----------------------+---------------------
 2       7-4    b15     | 9      57     8      |a14     3      6     
 34579   479     1359   | 1245   6      12457  | 8      249    1459   
 459     8       6      | 1245   3      1245   | 124    7      1459   

(4=1)r7c7 - (1=5)r7c3 - r56c3 = (5-4)r6c1 = r5c2 => -4 r7c2; stte

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