Sudoku Puzzles

17:08 easy tough today for a change!

10:28

But if x-wing link h3,b6 forbids c4=6 we see I2=1 or b7=5 so in any case I1=2 is forbidden, allowing the weakly linked 3's to confirm s2 is locked. Knowing that, we can see that neither g1,I1=4 leading to E1=4, consequently easy to 81. Its a no-brainer, really. Happy St. Pat's day!

Steve: I am afraid your ingenious depth 11 solution of yesterday's puzzle needs a more complicated matrix pattern than the one I described above. Bruno and I have those too but they are too complicated to explain here.

DJ: I am not sure what you mean by 'color.' Our statement is this: if there is a square matrix whose entries are sets of candidates (possibly empty) so that the union in each row is a strong set, and in every column but one each pair of entries is in conflict, then the union of entries in the remaining column is a strong set. To see this, argue by contradiction and use Pigeonhole Principle.

Exactly what puzzle is Mensa Man talking about?

Andrei: I meant numbers or atoms. I wasn't able immediately to relate your example to the POU theorem. I think I get it now.

The pigeonhole theorem is exactly what the 'Almost Locked Sets' idea uses, every single time. The generalization of same requires either a contradictory proof, or one could easily construct a proof by induction after showing validity on a trivial set. I think so, anyway.

Could anyone tell me how you guys approach to these puzzles using matrices.I dont use no particular strategy to solve,I guess, I have completed it in a crude way.

Wish I could figure out your 'code' for solving, because it seems like so much Greek to me! I'm not a Mensa member or even close! But I sure enjoy solving, even with check moves. And I enjoy the descussions about ways to solve.

21:46 Good mAen all!

19.33 i got to 46 filled and then looked at some of the solutions to help me get 'unstuck' it seems so easy when you have the solution there...but i am starting to get the toughs sometimes...many thanks to all the sudokers who have assisted me in the past week.
also, for the uninitiated, the More...

I'm with Karen from NR OH - Steve and the gang - what are you all talking about???

Happy Paddy's Day to my favourite geeks!!!

De\r Steve & Andrei I love reading your posts...unfortunatly they make no sense to me what so ever....needless to say I am no where near solving the puzzle....will have to look on a site for 'idiots guide'....back to my comfort zone mediun/hard!! cheers all!

24:29 - I actually think I solved this one without using x-wing or y-wing or any of those techniques that I'm just beginning to understand. Is that possible, or did I just make a lucky mistake?

Either today's tough was easier than usual or I'm getting better at this.

7.54 thought that was straight forward and quite easy for a toughie
who are the cheeky pair in the picture
have a great day/night one and all
Happy St Patricks day to those still on the 17th

easy...'touching' picture

16:10 cute boys

17:49 after setup. Much better than yesterday's tough!

ok

10:54

July 2, 2007.

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