AU Tough February 23, 2013

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AU Tough February 23, 2013

Code: Select all
` *-----------* |19.|..3|..6| |...|.5.|.2.| |..3|...|.7.| |---+---+---| |5..|4..|...| |..8|.1.|7..| |...|..8|..9| |---+---+---| |.3.|...|6..| |.4.|.8.|...| |2..|3..|.51| *-----------*`
dan

ArkieTech

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

Re: AU Tough February 23, 2013

Code after basics:
Code: Select all
` *--------------------------------------------------------------------* | 1      9      2      | 78     47     3      | 5      48     6      | | 4678   678    467    | 1689   5      1469   | 19     2      3      | | 468    5      3      | 12689  2469   12469  | 19     7      48     | |----------------------+----------------------+----------------------| | 5      1267   9      | 4      2367   267    | 238    16     28     | | 34     26     8      | 269    1      269    | 7      34     5      | | 3467   1267   467    | 5      2367   8      | 234    16     9      | |----------------------+----------------------+----------------------| | 789    3      15     | 127    247    12457  | 6      489    2478   | | 679    4      15     | 1267   8      12567  | 23     39     27     | | 2      678    67     | 3      4679   4679   | 48     5      1      | *--------------------------------------------------------------------*`

AAIC with (49=8)r7c8
[(9=4)r7c8-(4=8)r9c7-r9c2=8r7c1 => r7c1<>9] = [8r7c8-r9c7=r4c7-(8=2)r4c9-r78c9=(2-3)r8c7=(3-9)r8c8=9r7c8 Conflict => r7c8<>9]
Thus AIC is true => r7c1<>9

Ted

Edit: After my initial post, I re-visited the puzzle and found an ANS that is less messy than the AAIC.

ANS(9=48)r7c8,r9c7-(48=27)r78c9-(2=8)r4c9-r4c7=r9c7-r9c2=8r7c1 => 7c1<>9
tlanglet
2010 Supporter

Posts: 538
Joined: 29 May 2010

Re: AU Tough February 23, 2013

Code: Select all
` *--------------------------------------------------------------------* | 1      9      2      | 78     47     3      | 5      48     6      | | 4678   678    467    | 1689   5      1469   | 19     2      3      | | 468    5      3      | 12689  2469   12469  | 19     7      48     | |----------------------+----------------------+----------------------| | 5      1267   9      | 4      2367   267    | 238    16     28     | | 34     26     8      | 269    1      269    | 7     c34     5      | | 3467   1267   467    | 5      2367   8      | 23-4   16     9      | |----------------------+----------------------+----------------------| | 789    3      15     | 127    247    12457  | 6      89-4   2478   | |b679    4      15     | 1267   8      12567  | 23    c39     27     | | 2     b678   b67     | 3      4679   4679   |a48     5      1      | *--------------------------------------------------------------------*als xy-wing(4=8)r9c7-(8=3)r9c23,r8c1-(3=4)r58c8 => -4r6c7,r7c8; steoops  :oops: (4=8)r9c7-(8=9)r9c23,r8c1-(9=4)r58c8 => -4r6c7,r7c8; ste`

Thanks Danny
Last edited by ArkieTech on Sat Feb 23, 2013 4:56 pm, edited 1 time in total.
dan

ArkieTech

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

Re: AU Tough February 23, 2013

ArkieTech wrote:(4=8)r9c7-(8=9)r9c23,r8c1-(9=4)r58c8 => -4r6c7,r7c8
daj95376
2014 Supporter

Posts: 2624
Joined: 15 May 2006

Re: AU Tough February 23, 2013

Code: Select all
` *--------------------------------------------------------------------* | 1      9      2      | 78     47     3      | 5      48     6      | | 4678  #678   #467    | 1689   5      1469   | 19     2      3      | | 468    5      3      | 12689  2469   12469  | 19     7      48     | |----------------------+----------------------+----------------------| | 5     *1267   9      | 4      2367   267    | 238   #16     28     | | 34    *26     8      | 269    1      269    | 7      34     5      | | 3467  #1267  #467    | 5      2367   8      | 234   #16     9      | |----------------------+----------------------+----------------------| | 789    3      15     | 127    247    12457  | 6      489    2478   | | 679    4      15     | 1267   8      12567  | 23     39     27     | | 2     #678   #67     | 3      4679   4679   | 48     5      1      | *--------------------------------------------------------------------*`

For Ted:
Did you notice the 67 and 16 DP's (r6c123<>6 and r46c2<>6), which lead to a 6 in r5c2?
Solves with xyz-wing and 3 w-wings then.
eleven

Posts: 2273
Joined: 10 February 2008

Re: AU Tough February 23, 2013

Eleven, I can find 2x2 DPS at:
1. r7c36, r8c36 => r87c6 <> 1
2. r4c82, r6c82 => r64c2 <> 6
3. r2c76, r3c76 => r32c6 <> 9

but I'm having trouble understanding the eliminations you mention for r269c23. Can you possibly explain further?

Thanks, Phil
pjb
2014 Supporter

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Location: Sydney, Australia

Re: AU Tough February 23, 2013

pjb wrote:but I'm having trouble understanding the eliminations you mention for r269c23. Can you possibly explain further?

Sorry, was not clear enough. There are 3 potential UR's 67 in columns 23, so 6 or 7 has to be in the rest of the column cells, i.e. either r4c2=67 or r5c2=6. Since r4c2=67 implies r6c8=6 (through the 16 DP), the 6 can be eliminated from r6c123.
6r5c2=DP=(67-1)r4c2=1r4c8-(1=6)r6c8 => r6c123<>6

Oops, bloody mistake. It's not true, that 6 or 7 has to be in the rest of the column cells to prevent one of the 3 DP's.
Last edited by eleven on Mon Feb 25, 2013 5:42 pm, edited 1 time in total.
eleven

Posts: 2273
Joined: 10 February 2008

Re: AU Tough February 23, 2013

Code: Select all
`*--------------------------------------------------------------------* | 1      9      2      | 78     47     3      | 5      48     6      | | 4678   678    467    | 1689   5      1469   | 19     2      3      | | 468    5      3      | 12689  2469   12469  | 19     7      48     | |----------------------+----------------------+----------------------| | 5      1267   9      | 4      2367   267    | 238    16     28     | | 34     26     8      | 269    1      269    | 7      34     5      | | 3467   1267   467    | 5      2367   8      | 234    16     9      | |----------------------+----------------------+----------------------| | 789    3      15     | 127    247    12457  | 6      489    2478   | | 679    4      15     | 1267   8      12567  | 23     39     27     | | 2      678    67     | 3      4679   4679   | 48     5      1      | *--------------------------------------------------------------------*`

9r8c1=(9-3)r8c8=(3-4)r5c8=4r6c7-(4=8)r9c7-(8=67)r9c23 : =>r8c1=9 ste
aran

Posts: 334
Joined: 02 March 2007