The New Sudoku Players' Forum

[mith]

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+-------+-------+-------+
| . . . | 3 . 1 | . . . |
| . 4 1 | . 5 . | . 9 . |
| 2 . . | . 6 . | . . . |
+-------+-------+-------+
| . . . | 5 . . | 3 . . |
| . 5 . | . . . | . 8 . |
| . . 9 | . . 7 | . . . |
+-------+-------+-------+
| . . . | . 9 . | . . 3 |
| . 2 . | . 3 . | 8 4 . |
| . . . | 6 . 2 | . . . |
+-------+-------+-------+
...3.1....41.5..9.2...6.......5..3...5.....8...9..7.......9...3.2..3.84....6.2...

[Cenoman]

Code: Select all

 +-------------------+--------------------+-----------------------+
 | d578   9     6    |  3     247    1    |  2457  c257   24578   |
 |  3     4     1    |  27    5      8    |  6      9     27      |
 |  2     78    58   |  47    6      9    |  1457   3     14578   |
 +-------------------+--------------------+-----------------------+
 |  178  a178*  24   |  5     1248   6    |  3     a12*   9       |
 |  6     5     24   |  9     124    3    |  1247   8     1247    |
 |  18    3     9    |  248   1248   7    |  1245   6     1245    |
 +-------------------+--------------------+-----------------------+
 | e58-1  6     58   |  78    9      4    |  127   a127*  3       |
 |  9     2     7    |  1     3      5    |  8      4     6       |
 |  4    a18*   3    |  6     78     2    |  9     b157   157     |
 +-------------------+--------------------+-----------------------+

Almost kite
[(1)r9c2 = r4c2 - r4c8 = r7c8] = (1-5)r9c8 = r1c8 - r1c1 = (5)r7c1 => -1 r7c1; ste

[mith]

Nice; worth noting you could also get -1r4c2 from the same cells/links:

[(1)r4c8 = r7c8 - r7c1 = r9c2] = (1-5)r9c8 = r1c8 - r1c1 = (5)r7c1 [edit]corrected below: (5-1)r7c1 = (1)r9c2[/edit]

[denis_berthier]

I expected a lot of fish, but I get only two:

Hidden Text: Show

***********************************************************************************************
*** SudoRules 20.1.s based on CSP-Rules 2.1.s, config = SFin
*** Using CLIPS 6.32-r773
***********************************************************************************************
22 singles
138 candidates, 562 csp-links and 562 links. Density = 5.95%
whip[1]: r9n5{c9 .} ==> r7c8 ≠ 5, r7c7 ≠ 5
naked-pairs-in-a-column: c3{r3 r7}{n5 n8} ==> r4c3 ≠ 8, r1c3 ≠ 8, r1c3 ≠ 5
naked-single ==> r1c3 = 6
hidden-single-in-a-column ==> r5c1 = 6
whip[1]: r5n7{c9 .} ==> r4c8 ≠ 7
finned-x-wing-in-columns: n1{c2 c8}{r4 r9} ==> r9c9 ≠ 1
finned-x-wing-in-rows: n7{r2 r7}{c4 c9} ==> r9c9 ≠ 7
stte

[SpAce]

I expected a lot of fish, but I get only two

I expected just one with black and white stripes. He was the best starfish pilot in the ocean, and a cunning warrior

[mith]

These πlot Fish have a mutualistic relationship with

Hidden Text: Show

5r9c9

, eating those pesky parasitic candidates so it can swim free!

[Cenoman]

...you could also get -1r4c2 from the same cells/links:
[(1)r4c8 = r7c8 - r7c1 = r9c2] = (1-5)r9c8 = r1c8 - r1c1 = (5)r7c1

I can see the links with the embedded chain, but what about the remote fin ?
[(1)r4c8 = r7c8 - r7c1 = r9c2] = (1-5)r9c8 = r1c8 - r1c1 = (5-1)r7c1 = (1)r9c2 => -1 r4c2 ??

[mith]

Yep, sorry, modified the kite part and forgot to modify the end.

[mith]

I'm not sure what the best way to write this is, but you can also do something like this:

(7)r9c8 = (r1c8 | r7c8) - (r1c5 & r7c4) = (7-8)r9c5 = (8-1)r9c2 = (r4c2 & r7c1) - (r4c8 | r7c8) = (1)r9c8 => -5r9c8

Which basically incorporates both finned x-wings.

[mith]

Yep, sorry, modified the kite part and forgot to modify the end.

(And this gives -1r9c8 as well of course, though that isn't sufficient on its own.)

[pjb]

Code: Select all

g578     9       6      | 3      247    1      | 2457  h257    24578 
 3       4       1      | 27     5      8      | 6      9      27     
 2       78      58     | 47     6      9      | 1457   3      14578 
------------------------+----------------------+---------------------
b78-1   b78-1    24     | 5     c1248   6      | 3     j12     9     
 6       5       24     | 9      124    3      | 1247   8      1247   
a18      3       9      | 248    1248   7      | 245-1  6      245-1   
------------------------+----------------------+---------------------
f158     6       58     | 78     9      4      | 127    127    3     
 9       2       7      | 1      3      5      | 8      4      6     
 4      e18      3      | 6     d78     2      | 9     i157    157   


(1=8)r6c1 - (8)r4c12 = (8)r4c5 - (8)r9c5 = (8-1)r9c2 = (1*-5)r7c1 = (5)r1c1 - (5)r1c8 = (5-1)r9*7c8 = (1)r4c8 => -1 r4c12, r6c79; stte

Phil

[SpAce]

I'm not sure what the best way to write this is, but you can also do something like this:

(7)r9c8 = (r1c8 | r7c8) - (r1c5 & r7c4) = (7-8)r9c5 = (8-1)r9c2 = (r4c2 & r7c1) - (r4c8 | r7c8) = (1)r9c8 => -5r9c8

Nothing wrong with that. It's probably the most readable way to write it. I might have written it like this:

(7)r9c8 = r17c8 - (7,7)r1c5,r7c4 = (78-1)r9c52 = (1,1)r4c2,r7c1 - r47c8 = (1)r9c8 => -5 r9c8

Note that it's actually a loop but yields no extra eliminations as such. It also contains two subchains, (7r9c8==7r9c5) and (1r9c2==1r9c8), which yield -17r9c9 if desired.

[SteveG48]

Code: Select all

 *----------------------------------------------------------------------*
 | d578    9      6      |  3      247    1      | 2457  e257    24578  |
 |  3      4      1      |  27     5      8      | 6      9      27     |
 |  2      78     58     |  47     6      9      | 1457   3      14578  |
 *-----------------------+-----------------------+----------------------|
 |cd178  cd178    24     |  5      1248   6      | 3     e12     9      |
 |  6      5      24     |  9      124    3      | 1247   8      1247   |
 | b18     3      9      |ah248   a1248   7      | 1245   6      1245   |
 *-----------------------+-----------------------+----------------------|
 |cf158    6    bf58     |bg78     9      4      | 127   f127    3      |
 |  9      2      7      |  1      3      5      | 8      4      6      |
 |  4      18     3      |  6      78     2      | 9      157    157    |
 *----------------------------------------------------------------------*


8r6c45 = (8r6c1)&((85)r7c34) - (5|8)r4c12,r7c1 = (715)r1c1,r4c12 - (5|1=27)r14c8 - (2|7=158)r7c138 - 8r7c4 = 8r6c4 => -8 r4c5,r6c1 ; stte