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telegraph 12/17/10
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storm_norm

Joined: 18 Oct 2007
Posts: 1741

Posted: Sat Dec 18, 2010 10:04 pm Post subject: telegraph 12/17/10

000430000006702004009010200803000060600050008090000402001020600900605800000043000

Code:

+-------+-------+-------+
| . . . | 4 3 . | . . . |
| . . 6 | 7 . 2 | . . 4 |
| . . 9 | . 1 . | 2 . . |
+-------+-------+-------+
| 8 . 3 | . . . | . 6 . |
| 6 . . | . 5 . | . . 8 |
| . 9 . | . . . | 4 . 2 |
+-------+-------+-------+
| . . 1 | . 2 . | 6 . . |
| 9 . . | 6 . 5 | 8 . . |
| . . . | . 4 3 | . . . |
+-------+-------+-------+

Play online

Marty R.

Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

Posted: Sun Dec 19, 2010 1:42 am Post subject:

Quote:

Implications of potential 24 DP in boxes 47; r5c3<>4

daj95376

Joined: 23 Aug 2008
Posts: 3854

Posted: Sun Dec 19, 2010 2:06 am Post subject:

Marty, I could not duplicate your elimination logic.

Code:

after basics
+--------------------------------------------------------------+
| 2 8 7 | 4 3 9 | 15 15 6 |
| 15 15 6 | 7 8 2 | 3 9 4 |
| 34 34 9 | 5 1 6 | 2 8 7 |
|--------------------+--------------------+--------------------|
| 8 147 3 | 2 9 147 | 157 6 15 |
| 6 1247 24 | 3 5 147 | 9 17 8 |
| 17 9 5 | 8 6 17 | 4 3 2 |
|--------------------+--------------------+--------------------|
| 34 57 1 | 9 2 8 | 6 457 35 |
| 9 234 24 | 6 7 5 | 8 14 13 |
| 57 6 8 | 1 4 3 | 57 2 9 |
+--------------------------------------------------------------+
# 34 eliminations remain

Regards, Danny

Marty R.

Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

Posted: Sun Dec 19, 2010 2:34 am Post subject:

Quote:

Marty, I could not duplicate your elimination logic.

Nobody ever can. I had a fuller grid and chalk up one more mistake. Embarassed

tlanglet

Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills

Posted: Sun Dec 19, 2010 3:31 am Post subject:

My first pass was a two stepper....

Quote:

Kraken cell (14)r4c2; r5c2<>7
(1)r4c2-(1=7)r6c1;
(4)r4c2-r5c3=r8c3-(4=1)r8c8-(1=7)r5c8;
(7)r4c2;

Coloring (7)

Ted

Marty R.

Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

Posted: Sun Dec 19, 2010 5:43 am Post subject:

Second go-round: Coloring (7); r4c2<>7 Coloring (7); r5c6<>7 W-Wing (14) exposed by above; r4c6, r5c23<>4 Danny, thanks again. Don't you or anyone else be shy about pointing these things out. I won't be offended and need all the help I can get.

peterj

Joined: 26 Mar 2010
Posts: 974
Location: London, UK

Posted: Sun Dec 19, 2010 12:50 pm Post subject:

I had a look at the skyscraper(7) move from a Broken Wing angle...

Code:

*------------------------------------------------------------*
| 2 8 7 | 4 3 9 | 15 15 6 |
| 15 15 6 | 7 8 2 | 3 9 4 |
| 34 34 9 | 5 1 6 | 2 8 7 |
|--------------------+-------------------+-------------------|
| 8 *(147) 3 | 2 9 &17-4 | *157 6 15 |
| 6 &1247 24 | 3 5 147 | 9 17 8 |
| *(17) 9 5 | 8 6 17 | 4 3 2 |
|--------------------+-------------------+-------------------|
| 34 57 1 | 9 2 8 | 6 457 35 |
| 9 234 24 | 6 7 5 | 8 14 13 |
| *57 6 8 | 1 4 3 | *57 2 9 |
*------------------------------------------------------------*
Broken wing in 7 marked with *; guardians with &

Guardians (7)r4c6, (7)r5c2 ; r4c2<>7, r5c6<>7
... and using the strong link...

ANP(4=17)r4c2|r6c1 - BrokenWing(7)[(7)r5c2=(7)r4c6] ; r4c6<>4

I now see from reading Marty's solution that this is essentially the same as colouring followed by a w-wing but anyway I had some fun! You can make it even more w-wing like by using the ANP in b5....

Code:

ANP(4=17)r4c2|r6c1 - BrokenWing(7)[(7)r5c2=(7)r4c6] - ANP(17=4)r56c6

daj95376

Joined: 23 Aug 2008
Posts: 3854

Posted: Sun Dec 19, 2010 4:18 pm Post subject:

Same pattern as Peter, but using a contradiction on one of the guardian candidates.

Code:

Broken Wing in <7> w/ 2x guardian cells:

Code:

+-----------------------------------+
| . . 7 | . . . | . . . |
| . . . | 7 . . | . . . |
| . . . | . . . | . . 7 |
|-----------+-----------+-----------|
| . *7 . | . . g7 | *7 . . |
| . g7 . | . . 7 | . 7 . |
| *7 . . | . . 7 | . . . |
|-----------+-----------+-----------|
| . 7 . | . . . | . 7 . |
| . . . | . 7 . | . . . |
| *7 . . | . . . | *7 . . |
+-----------------------------------+

However, ...

Code:

(7-2)r5c2 = (2)r5c3 - (2=4)r8c3 - (4=1)r8c8 - (1=7)r5c8 - (7)r5c2

Leaving r4c6=7 to crack the puzzle.

A 2-stepper:

Code:

Kite/Skyscraper/whatever for r4c2<>7

Chain from above ^

Leaving: r6c1=7 to crack the puzzle.

Regards, Danny

peterj

Joined: 26 Mar 2010
Posts: 974
Location: London, UK

Posted: Sun Dec 19, 2010 4:56 pm Post subject:

OK, seeing as there aren't enough puzzles for a Sunday afternoon... Sad

Anyone think this might be a 14-cell BUG-Lite? Laughing

As far as I can see every house has two of each candidate..

Code:

*-----------------------------------------------------------*
| 2 8 7 | 4 3 9 | *15 *15 6 |
| *15 *15 6 | 7 8 2 | 3 9 4 |
| 34 34 9 | 5 1 6 | 2 8 7 |
|-------------------+-------------------+-------------------|
| 8 *17+4 3 | 2 9 147 | *17+5 6 15 |
| 6 1247 24 | 3 5 *17+4 | 9 *-17 8 |
| *17 9 5 | 8 6 *17 | 4 3 2 |
|-------------------+-------------------+-------------------|
| 34 *57 1 | 9 2 8 | 6 *57+4 35 |
| 9 234 24 | 6 7 5 | 8 14 13 |
| *57 6 8 | 1 4 3 | *57 2 9 |
*-----------------------------------------------------------*

BUG-Lite+4
(5)r4c7 - (5=1)r4c9 ; r5c8<>1
(4)r7c8 - (4=1)r8c8 ; r5c8<>1
(4)r4c2 - (4)r2c3=r8c3 - (4=1)r8c8 ; r5c8<>1
(4)r5c6 - (4)r2c3=r8c3 - (4=1)r8c8 ; r5c8<>1

daj95376

Joined: 23 Aug 2008
Posts: 3854

Posted: Sun Dec 19, 2010 6:46 pm Post subject:

peterj wrote:

Anyone think this might be a 14-cell BUG-Lite?

Code:

I don't think so, but your cells lead to an interesting forcing network.

Code:

partially fill (*) cells starting w/ r2c1=1
r6c1 =7 forces r4c2<>7
r4c79=15 forces r4c2<>1
BUG can't form one possible pattern
However, r4c2=4 results
*--------------------------------------------------*
| 2 8 7 | 4 3 9 | 15 15 6 |
| 1* 5* 6 | 7 8 2 | 3 9 4 |
| 34 34 9 | 5 1 6 | 2 8 7 |
|----------------+----------------+----------------|
| 8 4# 3 | 2 9 47 | 15 6 15 |
| 6 124 24 | 3 5 47 | 9 17 8 |
| 7* 9 5 | 8 6 1 | 4 3 2 |
|----------------+----------------+----------------|
| 34 7* 1 | 9 2 8 | 6 45 35 |
| 9 234 24 | 6 7 5 | 8 14 13 |
| 5* 6 8 | 1 4 3 | 7* 2 9 |
*--------------------------------------------------*

Code:

partially fill (*) cells starting w/ r2c1=5
r6c1=1 forces r4c2<>1
r4c7=7 forces r4c2<>7
BUG can't form one possible pattern
However, r4c2=4 results
*--------------------------------------------------*
| 2 8 7 | 4 3 9 | 1* 5 6 |
| 5* 1* 6 | 7 8 2 | 3 9 4 |
| 34 34 9 | 5 1 6 | 2 8 7 |
|----------------+----------------+----------------|
| 8 4# 3 | 2 9 14 | 7* 6 15 |
| 6 247 24 | 3 5 147 | 9 1 8 |
| 1* 9 5 | 8 6 17 | 4 3 2 |
|----------------+----------------+----------------|
| 34 5* 1 | 9 2 8 | 6 47 3 |
| 9 234 24 | 6 7 5 | 8 14 13 |
| 7* 6 8 | 1 4 3 | 5* 2 9 |
*--------------------------------------------------*

Setting r4c2=4 cracks puzzle.

peterj

Joined: 26 Mar 2010
Posts: 974
Location: London, UK

Posted: Sun Dec 19, 2010 7:05 pm Post subject:

daj95376 wrote:

I don't think so, but your cells lead to an interesting forcing network.

Rats! Yes, I finally convinced myself I was wrong also...
I am still a long way from understanding how to spot DPs other than the ones that I have 'learnt rote'.

Danny, thanks for checking!

ronk

Joined: 07 May 2006
Posts: 398

Posted: Mon Dec 20, 2010 12:04 pm Post subject:

peterj wrote:

Anyone think this might be a 14-cell BUG-Lite? Laughing

As far as I can see every house has two of each candidate.

Code:

peterj wrote:

daj95376 wrote:

I don't think so, but ...

Rats! Yes, I finally convinced myself I was wrong also...
I am still a long way from understanding how to spot DPs other than the ones that I have 'learnt rote'.

peterj, your pattern IS a BUG-Lite. It's easy enough to show the below has two solutions.

Code:

. . . | . . . | ab ab .
ab ab . | . . . | . . .
. . . | . . . | . . .
----------+----------+----------
. ac . | . . . | ac . .
. . . | . . ac | . ac .
ac . . | . . ac | . . .
----------+----------+----------
. bc . | . . . | . bc .
. . . | . . . | . . .
bc . . | . . . | bc . .

daj95376

Joined: 23 Aug 2008
Posts: 3854

Posted: Mon Dec 20, 2010 7:35 pm Post subject:

ronk wrote:

peterj, your pattern IS a BUG-Lite. It's easy enough to show the below has two solutions.

Code:

I've filled in the BUG-Lite to this point based on r2c1=a. Please complete [b6].

Code:

. . . | . . . | b a .
a b . | . . . | . . .
. . . | . . . | . . .
----------+----------+----------
. a . | . . . | ac . .
. . . | . . c | . ac .
c . . | . . a | . . .
----------+----------+----------
. c . | . . . | . b .
. . . | . . . | . . .
b . . | . . . | c . .

[Edit: inserted and then removed comments on "supposed" loops.]

Last edited by daj95376 on Tue Dec 21, 2010 12:49 am; edited 3 times in total

ronk

Joined: 07 May 2006
Posts: 398

Posted: Mon Dec 20, 2010 7:50 pm Post subject:

daj95376 wrote:

ronk wrote:

peterj, your pattern IS a BUG-Lite. It's easy enough to show the below has two solutions.

Code:

Okay. I've filled in the BUG-Lite to this point based on r2c1=a. Please complete [b6].

Code:

Looks like I should have written "an even number of solutions." Smile

daj95376

Joined: 23 Aug 2008
Posts: 3854

Posted: Mon Dec 20, 2010 8:15 pm Post subject:

ronk wrote:

Looks like I should have written "an even number of solutions."

Did we cross wires on my example? I had hoped to show there is no way to legally complete [b6].

(Note: I added information to my post above.)

peterj

Joined: 26 Mar 2010
Posts: 974
Location: London, UK

Posted: Mon Dec 20, 2010 8:50 pm Post subject:

ronk wrote:

Looks like I should have written "an even number of solutions." Smile

Is zero technically even? Laughing

But even though the pattern seems to have no valid solution, does that still not mean that the logic presented is valid - since it is avoiding an illegal pattern? So more like a broken-wing than a classic DP?

daj95376

Joined: 23 Aug 2008
Posts: 3854

Posted: Mon Dec 20, 2010 10:57 pm Post subject:

[Withdrawn: I missed something with my "supposed" loops.] Last edited by daj95376 on Tue Dec 21, 2010 12:48 am; edited 1 time in total

ronk

Joined: 07 May 2006
Posts: 398

Posted: Tue Dec 21, 2010 12:36 am Post subject:

daj95376 wrote:

Maybe this was Ron's point -- two DP loops with two possible solutions each.

My point is that a BUG-Lite usually has two solutions, but no solution is also a possibility.

peterj

Joined: 26 Mar 2010
Posts: 974
Location: London, UK

Posted: Tue Dec 21, 2010 12:33 pm Post subject:

Is it relevant that part of this "BUG-Lite" pattern is overlaid on top of a Broken Wing pattern?

Code:

. . . | . . . | ab . .
ab . . | . . . | . . .
. . . | . . . | . . .
------------+----------+-----------
. *ac . | . . . | *ac . .
. . . | . . . | . . .
*ac . . | . . . | . . .
------------+----------+-----------
. . . | . . . | . . .
. . . | . . . | . . .
*bc . . | . . . | *bc . .

* marks the broken wing in "c" (7 in this case)

The simplest scenario would be if the "bc" in r9 were "ac". However, the existence of the "ab" bivalues in band 1 has the same effect making an illegal loop. Start at bottom left shows it most simply.

In this specific puzzle this illegal bivalue chain is stopped by (4)r4c2 and (5)r4c6 allowing the same elimination with two less streams.

daj95376

Joined: 23 Aug 2008
Posts: 3854

Posted: Tue Dec 21, 2010 2:40 pm Post subject:

ronk wrote:

My point is that a BUG-Lite usually has two solutions, but no solution is also a possibility.

I was unaware that a BUG/BUG-Lite/DP could have zero solutions. In that regard, I generated scenarios for cell r2c1.

Code:

scenario r2c1=a
. . . | . . . | b a .
a b . | . . . | . . .
. . . | . . . | . . .
----------+----------+----------
. a . | . . . | ac . .
. . . | . . c | . ac .
c . . | . . a | . . .
----------+----------+----------
. c . | . . . | . b .
. . . | . . . | . . .
b . . | . . . | c . .

Code:

scenario r2c1=b
. . . | . . . | a b .
b a . | . . . | . . .
. . . | . . . | . . .
----------+----------+----------
. c . | . . . | ac . .
. . . | . . a | . ac .
a . . | . . c | . . .
----------+----------+----------
. b . | . . . | . c .
. . . | . . . | . . .
c . . | . . . | b . .

Since neither of these scenarios is acceptable, there must be another candidate in one of these 14 cells that is true -- i.e., Peter's original scenario.

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