Happy 2009. Here is a challenge for you:

Conjecture: All Sashimi in rows have complementary almost-locked set eliminations in columns. These alternative eliminations always involve the complementary set of columns of the original Sashimi and may not be the same elimination.

Conjecture: All Sashimi in columns have complementary almost-locked set eliminations in rows. These alternative eliminations always involve the complementary set of rows of the original Sashimi and may not be the same elimination.

For each of these conjectures, the converse is not necessarily true.

Prove or disprove?

for discussion, see:

http://www.stolaf.edu/people/hansonr/sudoku/explain.htm#sashimi

Bob Hanson