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[ArkieTech]

Code: Select all

 *-----------*
 |..7|.1.|.3.|
 |34.|..5|.2.|
 |..5|...|7.4|
 |---+---+---|
 |.5.|.9.|...|
 |8..|5.7|..9|
 |...|.2.|.6.|
 |---+---+---|
 |1.2|...|6..|
 |.3.|1..|.92|
 |.9.|.8.|3..|
 *-----------*


Play/Print this puzzle online

[Leren]

Code: Select all

*--------------------------------------------------------------*
| 269   268   7      | 24689 1     24689  | 589   3     568    |
| 3     4     1689   | 6789  67    5      | 189   2     168    |
| 269   1268  5      | 23689 36    23689  | 7     18    4      |
|--------------------+--------------------+--------------------|
| 2467  5     1346   | 3468  9     13468  | 1248  1478  1378   |
| 8     126   1346   | 5     346   7      | 124   14    9      |
| 479   17    1349   | 348   2     1348   | 1458  6     13578  |
|--------------------+--------------------+--------------------|
| 1     78    2      | 349   345   349    | 6     45    78     |
|c57    3     468    | 1    b57    46     | 48    9     2      |
|d4567  9     46     |a2467  8     246    | 3    e145-7 17     |
*--------------------------------------------------------------*

L2 Wing: (7) r9c4 = (7-5) r8c5 = r8c1 - r9c1 = r9c8 => - 7 r9c8; stte

Leren

[Marty R.]

Code: Select all

+----------------+-----------------+-----------------+
| 269  268  7    | 24689 1   24689 | 589  3    568   |
| 3    4    1689 | 6789  67  5     | 189  2    168   |
| 269  1268 5    | 23689 36  23689 | 7    18   4     |
+----------------+-----------------+-----------------+
| 2467 5    1346 | 3468  9   13468 | 1248 1478 1378  |
| 8    126  1346 | 5     346 7     | 124  14   9     |
| 479  17   1349 | 348   2   1348  | 1458 6    13578 |
+----------------+-----------------+-----------------+
| 1    78   2    | 349   345 349   | 6    45   78    |
| 57   3    468  | 1     57  46    | 48   9    2     |
| 4567 9    46   | 2467  8   246   | 3    1457 17    |
+----------------+-----------------+-----------------+


Play this puzzle online at the Daily Sudoku site

5r9c1=(5-7)r8c1=r8c5-(7=6)r2c5-(689=1)r2c379-(1478=5)r79c9,r8c7,r7c8=>r9c8<>5

[ronk]

Code: Select all

+----------------+-----------------+-----------------+
| 269  268  7    | 24689 1   24689 | 589  3    568   |
| 3    4    1689 | 6789  67  5     | 189  2    168   |
| 269  1268 5    | 23689 36  23689 | 7    18   4     |
+----------------+-----------------+-----------------+
| 2467 5    1346 | 3468  9   13468 | 1248 1478 1378  |
| 8    126  1346 | 5     346 7     | 124  14   9     |
| 479  17   1349 | 348   2   1348  | 1458 6    13578 |
+----------------+-----------------+-----------------+
| 1    78   2    | 349   345 349   | 6    45   78    |
| 57   3    468  | 1     57  46    | 48   9    2     |
| 4567 9    46   | 2467  8   246   | 3    1457 17    |
+----------------+-----------------+-----------------+


5r9c1=(5-7)r8c1=r8c5-(7=6)r2c5-(689=1)r2c379-(1478=5)r79c9,r8c7,r7c8=>r9c8<>5

Do all of the 1s in als r2c379 see 1r9c9?

[Marty R.]

Code: Select all

+----------------+-----------------+-----------------+
| 269  268  7    | 24689 1   24689 | 589  3    568   |
| 3    4    1689 | 6789  67  5     | 189  2    168   |
| 269  1268 5    | 23689 36  23689 | 7    18   4     |
+----------------+-----------------+-----------------+
| 2467 5    1346 | 3468  9   13468 | 1248 1478 1378  |
| 8    126  1346 | 5     346 7     | 124  14   9     |
| 479  17   1349 | 348   2   1348  | 1458 6    13578 |
+----------------+-----------------+-----------------+
| 1    78   2    | 349   345 349   | 6    45   78    |
| 57   3    468  | 1     57  46    | 48   9    2     |
| 4567 9    46   | 2467  8   246   | 3    1457 17    |
+----------------+-----------------+-----------------+


5r9c1=(5-7)r8c1=r8c5-(7=6)r2c5-(689=1)r2c379-(1478=5)r79c9,r8c7,r7c8=>r9c8<>5

Do all of the 1s in als r2c379 see 1r9c9?

Of course they don't. But why do they have to? Because if they do then I'm going to have to unlearn and relearn everything I know about the subject, which isn't that much to begin with.

The ALS in r2 is intended to set r2c9=1 and at that point I would've thought that I'm done with the other 1s in r2. (I could set r2c9=1 by other means too complex for me to notate). Then the 1 in r2c9 leads into the ALS in box 9.

What is the mistake I made and what rule did I break?

[ronk]

Marty, we've had this discussion before I think. In this case, the most obvious indication of a problem is that when r9c9=1, the set <1689> remaining in r2c379 is not locked.

[Marty R.]

Marty, we've had this discussion before I think.

We probably have. Bear with me, as I don't understand this stuff; what I do with notation and ALS's is by rote.

[Marty R.]

Code: Select all

+----------------+-----------------+-----------------+
| 269  268  7    | 24689 1   24689 | 589  3    568   |
| 3    4    1689 | 6789  67  5     | 189  2    168   |
| 269  1268 5    | 23689 36  23689 | 7    18   4     |
+----------------+-----------------+-----------------+
| 2467 5    1346 | 3468  9   13468 | 1248 1478 1378  |
| 8    126  1346 | 5     346 7     | 124  14   9     |
| 479  17   1349 | 348   2   1348  | 1458 6    13578 |
+----------------+-----------------+-----------------+
| 1    78   2    | 349   345 349   | 6    45   78    |
| 57   3    468  | 1     57  46    | 48   9    2     |
| 4567 9    46   | 2467  8   246   | 3    1457 17    |
+----------------+-----------------+-----------------+


Play this puzzle online at the Daily Sudoku site

5r9c1=(5-7)r8c1=r8c5-(7=6)r2c5-(689=1)r2c379-(1478=5)r79c9,r8c7,r7c8=>r9c8<>5

Without the ALS in r2.

5r9c1=(5-7)r8c1=r8c5-(7=6)r2c5 [=>r2c9<>6] -(63=4)r35c5-(4=1)r5c8-(1=8)r3c8=r2c9<>8=1-(1478=5)r79c9,r8c7,r7c8=>r9c8<>5

There is probably something wrong here, but I don't know what to do in c5 when the chain goes up and then comes down.