- Code: Select all
*---*
|1..|
|2..|
|3..|
|---+
|.4.|
|.5.|
|.6.|
|---+
|...|
|...|
|...|
*---*
*----------------------------------*
| 1 789 456789 |
| 2 789 456789 |
| 3 789 456789 |
|----------------------------------|
| 789 4 123789 |
| 789 5 123789 |
| 789 6 123789 |
|----------------------------------|
| 456789 123789 123456789 |
| 456789 123789 123456789 |
| 456789 123789 123456789 |
*-----------------------------------*
There is already enough info to reduce the number of candidates considerably, since triples can be shown to exist here. Thus we exclude 789 from r123456c3 and from r789c12, and then r789c3 can only be 789.
They aren't always this easy to spot, but when they are, don't miss them!