## Vanhegan Fiendish January 8, 2013 (skipped)

Post puzzles for others to solve here.

### Re: Vanhegan Fiendish January 8, 2013 (skipped)

Long ago, Luke present a solution based on an oddagon and I tried to add it to my bag of tricks but over time it fell out through a hole in my bag. However, this post renews my interest.

Thanks Don

Ted
tlanglet
2010 Supporter

Posts: 538
Joined: 29 May 2010

### Re: Vanhegan Fiendish January 8, 2013 (skipped)

David P Bird wrote:Other names for "Broken Wings" are "Oddagons" and "Impossible Loops".

They derive a strong inference that one of the guardians must be true and so can be notated in much the same way as other deadly patterns.

I would therefore write:

(2)r5c8 =[(2)BW:r69c8,r9c1,r68c3]= (2)r3c8,r9c9 - (2)r1c9 etc.

Note the guardians are considered to be external to the pattern and the strong link between them is justified by identifying the pattern.

edit: removed initial response.

Now I understand your notation more clearly and it expresses what I intended better than mine (translating the notation broadly): the BW would be true if (2)r5c8 isn't true and (2)r3c8,(2)r9c9 aren't true so if (2)r5c8 isn't true then (2)r1c9 can't be true because it would eliminate (2)r3c8,(2)r9c9 etc.[/i].

Revised notation using David's changes:

(2)r5c8 = [(2)BW:r69c8,r9c1,r68c3] = (2)3c8,r9c9 - (2)r1c9=r9c9-r9c1=(2-6)r8c3=r6c3-r6c5=(6)r5c4 => -2r5c4 stte
Last edited by DonM on Sun Jan 20, 2013 2:46 am, edited 2 times in total.
DonM
2013 Supporter

Posts: 475
Joined: 13 January 2008

### Re: Vanhegan Fiendish January 8, 2013 (skipped)

tlanglet wrote:Long ago, Luke present a solution based on an oddagon and I tried to add it to my bag of tricks but over time it fell out through a hole in my bag. However, this post renews my interest.

Thanks Don

Ted

Glad to replace the trick in your repaired bag- If I recall, that was an oddagon/BW that Luke presented to the tune of 'Blackbirds singing in the dead of night...'
DonM
2013 Supporter

Posts: 475
Joined: 13 January 2008

### Re: Vanhegan Fiendish January 8, 2013 (skipped)

(2)r5c8 =[(2)BW:r69c8,r9c1,r68c3]= (2)3c8,r9c9 - (2)r1c9 etc.

What is highlighted in blue represents a justified strong link. ie =[Some Pattern]= is a single strong link derived from that pattern.
To make my chains reader friendly, I add spaces on either side of links between cells, but here there are no spaces between the square braces and the link symbol which makes them stand out. For those who don't like extra spaces, using a colour or bold type could serve just as well.
In AICs the links must alternate, and when they don't appear to at first glance, the second glance should soon tell the story.

In words: guardian 1 and guardians 2 & 3 can't all be false, because of the deadly pattern threat.

This isn't the only notation option, but whatever way is used will attract critics. The most important thing is picking one that is versatile enough to hand every type of derived inference – which this one does.
David P Bird
2010 Supporter

Posts: 1043
Joined: 16 September 2008
Location: Middle England

### Re: Vanhegan Fiendish January 8, 2013 (skipped)

David P Bird wrote:Note the guardians are considered to be external to the pattern and the strong link between them is justified by identifying the pattern.

So if you use a turbot fish (skyscraper, kite), be aware, that you destroy an impossible pattern, which might help you per guardians.
(on the other hand of course there are impossible patterns with usefull guardians, where there is no turbot fish elimination)
eleven

Posts: 2273
Joined: 10 February 2008

### Re: Vanhegan Fiendish January 8, 2013 (skipped)

[Withdrawn: I made a mistake in supporting a Broken Wing pattern that wasn't based on a single-digit.]
Last edited by daj95376 on Tue Jan 22, 2013 5:42 am, edited 1 time in total.
daj95376
2014 Supporter

Posts: 2624
Joined: 15 May 2006

### Re: Vanhegan Fiendish January 8, 2013 (skipped)

daj95376 wrote:DonM's Broken Wing pattern is interesting ... and not the only one present. Congratulations to DonM for the find!

Thanks Danny. In my experience with more basic usable Broken Wing/oddagon patterns like this, you can often re-arrange cells using the same digits (as in the 2s here) to come up with other BWs, but almost always I find that you end up with the same number of Guardians and much the same final solution.
DonM
2013 Supporter

Posts: 475
Joined: 13 January 2008

Previous