Sudoku Players' Forum (clone)

Hello everyone,

I have been an eager amateur sudoku player for quite some time until today I got stuck on a nearly finished puzzle. Could anyone please give me a hint how to proceed with this? Not the complete solution, just what technique I need. Thank you in advance.

Kind regards,
Peter

https://ibb.co/GVFLZYF

Code: Select all

*-------------------------------*
| 6    4  2  | 8 3 5  | 1  7  9 |
| 78   9  78 | 4 2 1  | 6  5  3 |
| 5    1  3  | 9 7 6  | 2  4  8 |
|------------+--------+---------|
|*8-79 6  4  | 2 5 78 | 3  89 1 |
| 89   3  5  | 6 1 4  | 89 2  7 |
| 2    78 1  | 3 9 78 | 4  6  5 |
|------------+--------+---------|
| 1    2  89 | 7 6 3  | 5  89 4 |
| 3    78 6  | 5 4 9  | 78 1  2 |
| 4    5  79 | 1 8 2  | 79 3  6 |
*-------------------------------*

This is a BUG+1 situation and you can remove 7 & 9 from r4c1 as shown. You can find a description of the BUG principle here.

Leren