The New Sudoku Players' Forum

[Hajime]

Within this forum I came along this XV Sudoku (but I don't know where anymore)

Is comes from https://www.puzzlemix.com/playgrid.php?id=94200&type=xv
It is classified "moderate".
After basics and some XV constraints/restrictions, my interim result below is only solvable with forcing chains or nets:

Code: Select all

   +-----------+--------+---------+ 
   | 3  4    9 | 6  2  1|57  57  8| 
   | 8  1    6 | 7  3  5| 9  4   2| 
   |57  57   2 | 8  4  9| 6  1   3| 
   +-----------+--------+---------+ 
   |57 238  57 | 4  9 23| 1 238  6| 
   | 4  9   38 | 1  6 23|37 278  5| 
   | 6  23   1 | 5 78 78| 4  23  9| 
   +-----------+--------+---------+ 
   | 2  6   78 | 9 78  4|35  35  1| 
   | 1  38   4 |23  5  6|28  9   7| 
   | 9  57 3578|23  1 78|28  6   4| 
   +------------------------------+ 


Do I miss something?

SiSeSoSu code:

Hidden Text: Show

Code: Select all

#1//B4,XV
....2...............................4.......5...............................1....
............X.......X..........................................................X.
.V..V...X.......VV............V.V.X.X....X...........X.....X...X..V..X...........


[urhegyi]

There's no X between R9C6 and R9C7 so R9C6=8 and R9C7=2 is not possible!

[Hajime]

There's no X between R9C6 and R9C7 so R9C6=8 and R9C7=2 is not possible!

Aha, thank you.
If r9c7=2 then r9c6 must be 7.
If r9c7=8 then r9c6 must be 7.
But that is the definition of a cell forcing chain, isn't? A very short chain