The New Sudoku Players' Forum

[ArkieTech]

Code: Select all

 *-----------*
 |.53|.1.|7..|
 |...|...|..9|
 |.6.|...|.81|
 |---+---+---|
 |..2|..9|..3|
 |...|462|...|
 |4..|8..|2..|
 |---+---+---|
 |84.|...|.5.|
 |3..|...|...|
 |..7|.5.|14.|
 *-----------*


Play/Print this puzzle online

[Leren]

Code: Select all

*--------------------------------------------------------------------------------*
| 9       5       3        | 6       1       8        | 7       2       4        |
| 127     127     8        | 257     4       57       | 6       3       9        |
| 27      6       4        | 2379    29      37       | 5       8       1        |
|--------------------------+--------------------------+--------------------------|
| 156     8       2        |b15      7       9        | 4      a16      3        |
| 157     3       19       | 4       6       2        | 8       179     57       |
| 4       179     169      | 8       3      c15       | 2       1679   d57-6     |
|--------------------------+--------------------------+--------------------------|
| 8       4       169      | 1279    29      167      | 3       5       27       |
| 3       12      5        | 127     8       4        | 9       67      267      |
| 26      29      7        | 239     5       36       | 1       4       8        |
*--------------------------------------------------------------------------------*

h-wing: (6=1) r4c8 - (1=5) r4c4 - r6c6 = r6c9 => r6c9 <> 6; stte

Leren

[eleven]

Code: Select all

 *-------------------------------------------------*
 | 9    5    3    | 6     1   8    | 7  2     4    |
 | 127  127  8    | 257   4   57   | 6  3     9    |
 | 27   6    4    | 2379  29  37   | 5  8     1    |
 |----------------+----------------+---------------|
 | 156  8    2    | 15    7   9    | 4 *16    3    |
 | 157  3   #19   | 4     6   2    | 8 #179   57   |
 | 4    179 #169  | 8     3   15   | 2 #1679  567  |
 |----------------+----------------+---------------|
 | 8    4   *169  | 1279  29  167  | 3  5     27   |
 | 3    12   5    | 127   8   4    | 9  67    267  |
 | 26   29   7    | 239   5   36   | 1  4     8    |
 *-------------------------------------------------*

Just for fun.

UR19 in r56c38, external candidates 19r7c3 and 1r4c8
1r4c8-(1=5)r4c4
||
1r7c3-r7c46=r8c4-(1=5)r4c4
||
9r7c3-(9=6)r9c12-(6=5)r239c6
(-> 5r4c4=5r2c6)
=> r2c4,r6c6<>5

[Marty R.]

Code: Select all

+-------------+-------------+------------+
| 9   5   3   | 6    1  8   | 7 2    4   |
| 127 127 8   | 257  4  57  | 6 3    9   |
| 27  6   4   | 2379 29 37  | 5 8    1   |
+-------------+-------------+------------+
| 156 8   2   | 15   7  9   | 4 16   3   |
| 157 3   19  | 4    6  2   | 8 179  57  |
| 4   179 169 | 8    3  15  | 2 1679 567 |
+-------------+-------------+------------+
| 8   4   169 | 1279 29 167 | 3 5    27  |
| 3   12  5   | 127  8  4   | 9 67   267 |
| 26  29  7   | 239  5  36  | 1 4    8   |
+-------------+-------------+------------+


Play this puzzle online at the Daily Sudoku site

(2=7)r7c9-(7=6)r8c8-r4c8=r4c1-(6=2)r9c1-r23c1=r2c2
Transport 2r7c9-r7c45=r89c4=>r2c4<>2

A bit of explanation because this was notationally challenging. The first line shows (I hope) that r7c9=2=>r2c2=2. The second line represents a transport from r7c9 to r89c4.

[eleven]

For an AIC you just can add the second line at the left side of the first, switching the direction.
2r89c4=r7c45-(2=7)r7c9-(7=6)r8c8-r4c8=r4c1-(6=2)r9c1-r23c1=r2c2

[Marty R.]

For an AIC you just can add the second line at the left side of the first, switching the direction.
2r89c4=r7c45-(2=7)r7c9-(7=6)r8c8-r4c8=r4c1-(6=2)r9c1-r23c1=r2c2

Thanks! I wish I'd have thought of that.

[pjb]

Eleven wrote:

Just for fun.

UR19 in r56c38, external candidates 19r7c3 and 1r4c8
1r4c8-(1=5)r4c4
||
1r7c3-r7c46=r8c4-(1=5)r4c4
||
9r7c3-(9=6)r9c12-(6=5)r239c6
(-> 5r4c4=5r2c6)
=> r2c4,r6c6<>5

Dear Eleven

I don't know if it is just me, But I am struggling to understand the underlying logic here. While I can appreciate that the 1r4c8, 1r7c3 and 9r7c3 all lead to r4c4 = 5, I'm unclear how they are brought together by the potential UR. Could you please help?

Phil

[Marty R.]

Code: Select all

 *-------------------------------------------------*
 | 9    5    3    | 6     1   8    | 7  2     4    |
 | 127  127  8    | 257   4   57   | 6  3     9    |
 | 27   6    4    | 2379  29  37   | 5  8     1    |
 |----------------+----------------+---------------|
 | 156  8    2    | 15    7   9    | 4 *16    3    |
 | 157  3   #19   | 4     6   2    | 8 #179   57   |
 | 4    179 #169  | 8     3   15   | 2 #1679  567  |
 |----------------+----------------+---------------|
 | 8    4   *169  | 1279  29  167  | 3  5     27   |
 | 3    12   5    | 127   8   4    | 9  67    267  |
 | 26   29   7    | 239   5   36   | 1  4     8    |
 *-------------------------------------------------*

Just for fun.

UR19 in r56c38, external candidates 19r7c3 and 1r4c8
1r4c8-(1=5)r4c4
||
1r7c3-r7c46=r8c4-(1=5)r4c4
||
9r7c3-(9=6)r9c12-(6=5)r239c6
(-> 5r4c4=5r2c6)
=> r2c4,r6c6<>5

Seeing as Phil brought up the subject I decided to look a little closer. I hardly qualify as an expert on UR external analysis, but don't you have to account for the 9 in r6c2 with respect to r6c8?

[pjb]

I think I have it. If all 3 are false, then
if -19r7c3, then r7c3 = 6 and r6c3 = 19
if -1r4c8, then r4c8 = 6, r8c8 = 7, then r56c8 both = 19 giving a deadly pattern.

therefore at least one of 1r7c3, 9r7c3 and 1r4c8 has to be true
but since r4c5 = 5 when any one of these is true, then r4c5 = 5 and r2c4,r6c6<>5

Agood learning exercise
Phil