## Vanhegan fiendish October 21,2012

Post puzzles for others to solve here.

### Vanhegan fiendish October 21,2012

Code: Select all
` *-----------* |.1.|8..|7..| |.4.|..2|.56| |2..|6..|...| |---+---+---| |.6.|.3.|4.8| |...|481|...| |1.4|.9.|.7.| |---+---+---| |...|..7|..9| |37.|5..|.8.| |..6|..8|.3.| *-----------* `
dan

ArkieTech

Posts: 3355
Joined: 29 May 2006
Location: NW Arkansas USA

### Re: Vanhegan fiendish October 21,2012

Code: Select all
`+-------------+-------------+-------------+| 6   1   59  | 8  45   349 | 7    2  34  || 78  4   3   | 19 17   2   | 189  5  6   || 2   59  78  | 6  1457 349 | 189  49 134 |+-------------+-------------+-------------+| 9   6   2   | 7  3    5   | 4    1  8   || 57  3   57  | 4  8    1   | 69   69 2   || 1   8   4   | 2  9    6   | 3    7  5   |+-------------+-------------+-------------+| 458 25  158 | 3  1246 7   | 1256 46 9   || 3   7   19  | 5  26   49  | 26   8  14  || 45  259 6   | 19 124  8   | 125  3  7   |+-------------+-------------+-------------+`

XY-Chain, r3c8=9-->r8c9=4; r13c9, r7c8<>4.

I'm going to take my first shot at notation; there's nothing simpler than this.

(4=9)r3c8-(9=5)r3c2-(5=9)r1c3-(9=1)r8c3-(1=4)r8c9-->r13c9, r7c8<>4.

Not sure if the above is correct but I also want to try a shortened version to see if it's valid.

9r3c8-9r3c2=9r1c3-(9=1)r8c3-(1=4)r8c9.
Marty R.

Posts: 1508
Joined: 23 October 2012
Location: Rochester, New York, USA

### Re: Vanhegan fiendish October 21,2012

Marty R. wrote:
Code: Select all
`+-------------+-------------+-------------+| 6   1   59  | 8  45   349 | 7    2  34  || 78  4   3   | 19 17   2   | 189  5  6   || 2   59  78  | 6  1457 349 | 189  49 134 |+-------------+-------------+-------------+| 9   6   2   | 7  3    5   | 4    1  8   || 57  3   57  | 4  8    1   | 69   69 2   || 1   8   4   | 2  9    6   | 3    7  5   |+-------------+-------------+-------------+| 458 25  158 | 3  1246 7   | 1256 46 9   || 3   7   19  | 5  26   49  | 26   8  14  || 45  259 6   | 19 124  8   | 125  3  7   |+-------------+-------------+-------------+`

XY-Chain, r3c8=9-->r8c9=4; r13c9, r7c8<>4.

I'm going to take my first shot at notation; there's nothing simpler than this.

(4=9)r3c8-(9=5)r3c2-(5=9)r1c3-(9=1)r8c3-(1=4)r8c9-->r13c9, r7c8<>4.

Not sure if the above is correct but I also want to try a shortened version to see if it's valid.

9r3c8-9r3c2=9r1c3-(9=1)r8c3-(1=4)r8c9.

Marty,

Fantastic

To me, the first version is 100% A-1 OK.

The second version has one small detail missing. The beginning and end of an AIC act as pincers given that you start and end the chain with a strong link. You do not show the beginning 4 in r3c8 as part of the starting strong link. Thus your version becomes

(4=9)r3c8-9r3c2=9r1c3-(9=1)r8c3-(1=4)r8c9-->r8c9=4; r13c9, r7c8<>4

As always, others can offer better details about the whys and wherefores, but you nailed it.
tlanglet
2010 Supporter

Posts: 538
Joined: 29 May 2010

### Re: Vanhegan fiendish October 21,2012

My solution is not as simple as Marty's but it is what I found after a couple of interesting and fun steps that were useless.

(1=9)r8c3-r8c6=r9c4-(9=1=7=8)r2c451-r7c1=8r7c3 => -1r7c3

Edited to add second solution on 10/23 after finding I had posted it on Daily Sudoku which seems to be up and running.

9r9c2=9r3c2-(9=4)r3c8-r7c8=(4-1)r8c9=(1-9)r8c3=9r9c2 => 9r9c2
Last edited by tlanglet on Wed Oct 24, 2012 3:17 am, edited 1 time in total.
tlanglet
2010 Supporter

Posts: 538
Joined: 29 May 2010

### Re: Vanhegan fiendish October 21,2012

Code: Select all
` *-----------------------------------------------------------* | 6     1     9=5   | 8    a45    349   | 7     2     34    | | 78    4     3     | 19    17    2     | 189   5     6     | | 2     59   c78    | 6    b1457  349   | 189   49    134   | |-------------------+-------------------+-------------------| | 9     6     2     | 7     3     5     | 4     1     8     | | 57    3    d57    | 4     8     1     | 69    69    2     | | 1     8     4     | 2     9     6     | 3     7     5     | |-------------------+-------------------+-------------------| | 458   25    158   | 3     1246  7     | 1256  46    9     | | 3     7     19    | 5     26    49    | 26    8     14    | | 45    259   6     | 19    124   8     | 125   3     7     | *-----------------------------------------------------------*m-wing(7=5)r5c3-r3c3=(5-7)r3c5=5r1c3 => -5r1c3; stte`
dan

ArkieTech

Posts: 3355
Joined: 29 May 2006
Location: NW Arkansas USA