The New Sudoku Players' Forum

[tommy]

Code: Select all

     
+---+---+---+     
|291|---|--8|     
|438|179|256|     
|-5-|482|391|     
+---+---+---+     
|--3|8--|---|     
|-2-|---|-8-|     
|-8-|--6|1--|     
+---+---+---+     
|872|9--|-3-|     
|91-|35-|--2|     
|3-5|---|-1-|     
+---+---+---+     


[Sped]

Code: Select all

 
 *--------------------------------------------------------------------*
 | 2      9      1      | 56     36     35     | 47     47     8      |
 | 4      3      8      | 1      7      9      | 2      5      6      |
 | 67     5      67     | 4      8      2      | 3      9      1      |
 |----------------------+----------------------+----------------------|
 | 1567   46A    3      | 8      1249   1457   | 45679  2467B  4579   |
 | 1567   2      4679   | 57     1349   13457  | 45679  8      34579  |
 | 57     8      479    | 257    2349   6      | 1      247    34579  |
 |----------------------+----------------------+----------------------|
 | 8      7      2      | 9      146    14     | 456    3      45     |
 | 9      1      46A    | 3      5      478    | 4678   467b   2      |
 | 3      46a    5      | 267    246    478    | 46789  1      479    |
 *--------------------------------------------------------------------*


Multiple colors on 6 eliminates the 6s in r4c2 and r8c3.

Above, the 6s in column 2 are conjugate i.e. the only two 6s in the column. They are marked "A" and "a" above. Likewise the 6s in box 7 are conjugate and marked "a" and "A". Either all the "A"s = 6 or the "a" = 6.

There is another set of conjugate 6s in column 8, which are marked "B" and "b". Since there has to be a 6 in column 8, either the "B" in r4c8 or the "b" in r8c8 must be a 6.

The "A" cells in the left side of the grid see both "B" and "b", therefore the "A" cells must be false for 6 and the "a" cell in r9c2 must be true for 6.

So r4c2<>6, r8c3<>6, r9c2=6, and it's all singles from there.

[tommy]

good morning sped.

Thank you for your response. I would like to know where i can find some readings on colors to help me fully understand your response.

I do want to improve my skills and I have a long way to go.

also does r4c2<>6 mean can not equal 6?

[Sped]

good morning sped.

Thank you for your response. I would like to know where i can find some readings on colors to help me fully understand your response.

I do want to improve my skills and I have a long way to go.

also does r4c2<>6 mean can not equal 6?

Hello.

Yes. r4c2<>6 means that r4c2 does not equal 6.

A good explanation multiple coloring can be found here:

http://www.setbb.com/phpbb/viewtopic.php?p=2575&mforum=sudoku#2575

[ravel]

This one can also be solved with 2 strong links (marked by Sped in columns 2 and 8, which eliminate 8 in r8c3), which are more common in puzzles than eliminations that can be done by multiple coloring, but not by strong links, so i would recommend to read this thread first.