2005/09/29 tough puzzle from sudoku.com.au


This one is equivalent to 09/12. Proof :

1) Take 09/12 grid, move rows 1 to 9 (1=bottom!) on new positions 9,7,8,4,5,6,2,3,1.

[Maple Plot] [Maple Plot]

2) Now move columns a to i (a=left!) of last grid on new positions b,c,a,f,e,d,i,g,h. Do you begin to feel like "déjà vu"?

[Maple Plot] [Maple Plot]

3) All that's left now is to renumber values 1,2,3,4,5,6,7,8,9 of last grid on 2,8,1,6,4,7,9,5,3 and you get exactly today's puzzle.

4) Now applying the same "dictionary" (changing rows, columns, values) to proof of 09/12 you will mechanically get a proof of today's. Try it !

See equivalent puzzles : 09/12, 09/26, 09/27, 09/29, 10/02 .

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