champagneThanks for your efforts – I'm sorry that I haven't matched them and have yet to make use of your new collections.

champagne wrote:The pattern is not the preferred pattern of David, but we have a partial use of the ABI loop.

The puzzle is a perfectly good JExocet.

Digit (7) offers no UR threat in columns 2 & 3 because (78)r1c23 is already established.

(5)r9c8 = (5)r6c8 – (5)r4c9 = (5#2)r4c23

(6)r9c8 = (6)r3c8 – (6)r2c9 = (6#2)r2c23

So these digits are incompatible => r7c23 <> 56

giving r7c2 = 7, r8c7 <> 7, and r8c6 <> 8 (which you didn't include.)

Your use of "partial Exocet" seems to describe the case when an Exocet is located which can't be fully reduced to a pair of digits in the base cells using ABI loops.

If that's right, then using ABI loops can give 3 possible outcomes:

(1) ABI Irreducible - no conflicts identified

(2) ABI Partially Reducible - some conflicts identified

(3) ABI Reducible - conflicts identified for all but one combination of digits.

These outcomes are not really Exocet properties, but belong to the ABI loop method.

- 0 – 0 – 0 – 0 -

I haven't been completely idle though and have been looking at puzzles with Exocets and SK loops.

..4.....9.1...3.7.6.....2.......8....5..3..8....1.5.....2.....4.7.3...1.9...7.6.. tarx0037,tarek 7.0 SK *BB r46c5 r2c4 r8c6

After SK Loop eliminations:

- Code: Select all
` *----------------------*----------------------*----------------------*`

| 3578 238 4 | 25678 158 1267 | 1358 356 9 |

>| 258 1 589 | 2469 2469 3 | 458 7 568 |<

| 6 389 3578 | 45789 158 1479 | 2 345 1358 |

*----------------------*----------------------*----------------------*

| 12347 2469 13679 | 24679 2469 # 8 | 13459 2469 123567 |

>| 1247 5 1679 | 24679 3 24679 | 149 8 1267 |<

| 23478 2469 36789 | 1 2469 # 5 | 349 2469 2367 |

*----------------------*----------------------*----------------------*

| 1358 368 2 | 5689 158 169 | 7 359 4 |

>| 458 7 568 | 3 2469 2469 | 589 1 258 |<

| 9 348 1358 | 2458 7 124 | 6 235 358 |

*----------------------*----------------------*----------------------*

24 - 69 49 - 26

Compatibility checks show that the base cells for (2469)Jexocet:r46c5,r2c4,r8c6 must hold either (29) or (46)

Now r46c8 (one side of a UR to be avoided) will hold just one instance of a base digit, so the second one must be true in r13c8 or r79c8. In turn this means that (35)r13c8 and (35)r79c8 must hold 1 truth each.

This then holds for the rest of the SK loop which I like to notate as a multi-sector locked set:

SK Loop: (38)c2,(46)b7,(58)r8,(29)b9,(35)c8,(46)b3,(58)r2,(29)b1 16 digits, 16 intersection cells.

Each box/line intersection will hold one truth from the digits shown for the line and one from those shown for the boxes.

This check is much quicker to perform than working through the complete SK loop looking for cross-loop conflicts in the cells in the other boxes – which I don't think works here anyway.