LA Times Diabolical January 18, 2013

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Re: LA Times Diabolical January 18, 2013

Postby Leren » Mon Jan 21, 2013 12:56 am

pjb wrote:I struggled with Leren's first solution until it occurred to me that the 4r27c3 should surely be 4r3c27. Interestingly, an alternate W wing is the same two 34's but transmitted via r12c5.

Phil


You caught me out having another dyslexic moment - I've fixed my post accordingly.

Thanks for spotting the error - Leren
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Re: LA Times Diabolical January 18, 2013

Postby eleven » Mon Jan 21, 2013 1:43 pm

DonM wrote:Just eye-balling your solution, it is not clear to me what the operative SIS (provided by the BW) is, and/or whether this a net. As you say, there are 7 guardians. From what I see, it would take 3 cells with a 5 to knock out the guardians which, to me, usually means having to use a net. I'd like to better understand your solution- is there a derived SIS you can point out?

In my eyes it is a net, because i need 4 simple chains (and the BW). All moves with 2 simple chains can also be written as a simple AIC.

I also would call your AIC a net, because in fact you need this additional short chain, that one of the 3 guardians lead to another. However this can be hidden with a clever formulation. But i would compare that with a simple net, which is started from the 3 occurances of a digit in a house.

On the other hand i could claim, that my move is a chain, because it only has 2 endpoints and i could write it in a way similar to
5r3c4-[r9c3=5r9c139&r2c5=r2c79])-BW=5[r7c8-(5=3)r7c5-3r8c5 | 5r5c8-(5=8)r5c1-(8=5)r1c1-(5=3)r8c1]=5r8c8
But i think, that is a net nevertheless and much harder to read.
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Re: LA Times Diabolical January 18, 2013

Postby DonM » Mon Jan 21, 2013 5:22 pm

eleven wrote:
DonM wrote:Just eye-balling your solution, it is not clear to me what the operative SIS (provided by the BW) is, and/or whether this a net. As you say, there are 7 guardians. From what I see, it would take 3 cells with a 5 to knock out the guardians which, to me, usually means having to use a net. I'd like to better understand your solution- is there a derived SIS you can point out?

In my eyes it is a net, because i need 4 simple chains (and the BW). All moves with 2 simple chains can also be written as a simple AIC.

I also would call your AIC a net, because in fact you need this additional short chain, that one of the 3 guardians lead to another. However this can be hidden with a clever formulation. But i would compare that with a simple net, which is started from the 3 occurances of a digit in a house.


Thanks for the explanation. I was more interested in understanding your solution than comparing it to mine. But with regards to mine, you're making it more complicated than it is: there is a direct relationship only between 2 digits- one of the guardians and another digit, that, if true, would remove the other two guardians. No clever formulation was necessary to hide anything more complicated than that.
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