a 2, then that cell cannot be a 2, too". But look at this one:
- Code: Select all
2-4 2-6 . | 2-4-6 . . | . . .
2-4-6 . . | . . . | . . .
. . . | . . . | . . .
-------------+---------------+-------------
. . . | . . . | . . .
. . . | . . . | . . .
. . . | . . . | . . .
-------------+---------------+-------------
. . . | . . . | . . .
. . . | . . . | . . .
. . . | . . . | . . .
You can't fill in any of the cells, but
r2c1 and r1c4 must be identical!
Here's a variation with four numbers:
- Code: Select all
2-4 2-6 2-8| 2-4-6-8 . . | . . .
2-4-6-8 . . | . . . | . . .
. . . | . . . | . . .
-------------+---------------+-------------
. . . | . . . | . . .
. . . | . . . | . . .
. . . | . . . | . . .
-------------+---------------+-------------
. . . | . . . | . . .
. . . | . . . | . . .
. . . | . . . | . . .
Thomas