BUG+3?

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Re: BUG+3?

Postby Yogi » Fri Nov 02, 2018 9:32 pm

Thanx
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BUG+3

Postby Yogi » Thu Dec 06, 2018 9:00 am

Thanx SpAce: I followed up on your suggestion of the 12 October puzzle as a study exercise in BUG+3 and came to the same position as the diagram in your post of 13 October. Interesting (but not critical) that the extra BUG-killing candidates in all of the 3-candidate cells are 6. My solution followed the classic path of simplifying to BUG+2 then finding a two-case verity that flows from both the remaining cells: Fin to a 6XWing at r7c1 => -6r8c2. Now 6r7c8 AND 6r8c1 => 6r5c2 stte.
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Re: BUG+3

Postby SpAce » Thu Dec 06, 2018 4:49 pm

Yogi wrote:Thanx SpAce: I followed up on your suggestion of the 12 October puzzle as a study exercise in BUG+3 and came to the same position as the diagram in your post of 13 October. Interesting (but not critical) that the extra BUG-killing candidates in all of the 3-candidate cells are 6. My solution followed the classic path of simplifying to BUG+2 then finding a two-case verity that flows from both the remaining cells: Fin to a 6XWing at r7c1 => -6r8c2.

Yes, that works. Did you also understand my solution using the BUG+3 directly? In that all three BUG-guardians see three common 6s which can all be eliminated yielding 2r7c1, 7r7c2 and 2r8c9.

Now 6r7c8 AND OR 6r8c1 => 6r5c2 stte.

Not 'AND' but 'OR'. That's very important! You probably meant that both of them lead to 6r5c2, which is correct in plain English, but when written as a logical implication it's interpreted as: 'if both 6r7c8 AND 6r8c1 are true then 6r5c2 is true'. That's a much more restrictive statement, because it would require us to know that both of the premises are actually true before forcing the conclusion. We don't know that -- we only know that at least one of them must be true, but that's enough for the conclusion.

Btw, I hope I'm not confusing you, but here's a pretty extreme BUG+23 (I used it for fun, not for any practical reasons): November 6, 2018.
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