05/10/12 tough puzzle from sudoku.com.au

This one is equivalent to 05/09/28. Proof :

1) Take 05/09/28 grid, exchange rows and columns : R1(bottom!)<-->Ca(left!), etc.

2) Now move rows 123456789 (1=bottom!) on new positions 321654987

3) Now move columns abcdefghi(a=left!) on new positions cbadefihg. Do you begin to feel like déjà vu?

4) All that's left now is to rename last grid's values 123456789 on 291437856 and you get exactly 05/10/12's puzzle.

Now applying the same "dictionary" (changing rows, columns, values) to proof of 05/09/28 you will mechanically get a proof of today's. Try it ! Or see the method explained step by step on 10/08 example.

See more illustrated examples of equivalence between puzzles : 09/26,09/29, 10/02, 10/03, 10/04.
See equivalent puzzles : 2005/09/17, 2005/09/21, 2005/09/28, 2005/10/04, 2005/10/06, 2005/10/11, 2005/10/12.