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immpy · Joined: 06 May 2017 Posts: 574

Another tough one...enjoy the puzzle.

ZeroAssoluto · Joined: 05 Feb 2017 Posts: 1019 Location: Rimini, Italy

Hi everyone,

immpy · Joined: 06 May 2017 Posts: 574

Very nice Gianni. I must admit to being stumped by this one (until I tried guessing). And my first guess was wrong, but I flipped to my other option and I was able to solve. But to attempt a guess means I couldn't solve otherwise.
I may possibly be on my way to understanding chains better; and possibly may be able to use them as a solving technique. This puzzle, in particular, sort of forced me to try and conquer chains. A good friend suggested that I take one inference of my starting point and draw a circle around it, continuing with circles around any and all inferences produced by this beginning. Then I should take the other inference from my starting point and draw a square around it, continuing with squares around any and all subsequent inferences. In this way I can follow the chain more clearly it seems, and I able to clearly make the necessary eliminations incurred by the chain.
This is exactly what Gianni has done in essence, only the circles and squares are missing....but they are quite handy for the paper and pencil solvers out there.

cheers...immp

dongrave · Joined: 06 Mar 2014 Posts: 572

I enjoyed that one too! I had the same grid after basics as Gianni. Then I used the chain (8-5)r2c1=(5-6)r1c2=r1c7-(6=3)r7c7-(3=8)r9c8-r9c4=r2c4 contradiction => r2c1<>8.

Clement · Posted: Mon Aug 20, 2018 5:27 pm Post subject: Challenging 081318

immpy · Joined: 06 May 2017 Posts: 574

I am definitely advancing along pertaining to chains and loops. I keep studying examples and the light-bulb is slowly becoming illuminated. I just need to have a breakthrough now, where I actually spot one in a puzzle, and use it to make correct eliminations and/or placements. This very puzzle was the key indeed to my progression.

cheers...immp