This was a difficult one!
* AB1 hi (789): otherwise NQ 1234 (all 4 digits required in box 1), conflict with B-Setti col 3
* NQ 6789 box 1; 5 req in AC2: eliminate from rest of col
* C3=6 (B power)
* B6!=37 because D5!=37 (B power)
* 7 is required in either D7 or D9. This will keep coming back.
* F-J5, if hi, must contain 9 (B-Setti 9 box 5) --> single 6 on H5, remove from rest of compartment
* CE: B9!=1, A9!=6
* HC 1: A9!=8, else B5=3, H5=6, H9=8
* HC 2: B5!=3, else A9=3, E9=4 (no 5 in box 5!), D7=3, E7=3, and we can't provide 456 in that compartment without B conflict
* HC 3: B5!=7, else A1=7, C7=7 (Setti 7), D9=7, B conflict 56 in box 6
* Setti 2: A9!=4 --> J9=9
* Settis 197: no 9 in box 7, no 1 in box 9/row G, no 9 in col 1, no 7 in box 3
* 5 req in DEF9, eliminate from rest of box
* HC 4: D7!=7, else DEF9 requires 45 + one of 3,6 --> E7=3, can't provide 456 without B conflict
* HP 45 @ C78
* Setti 4 @ H, box 9
... and the rest is easy
Solution/discussion of is.gd/kst_652_B
Re: Solution/discussion of is.gd/kst_652_B
I've had another go at the puzzle, trying to find an easier solution. The one major thing I could find is that HC2 (B5!=3) isn't needed. That eliminates the lengthiest chain from the solution. The HP45 towards the end isn't needed, either (although it's pretty obvious at that late stage, so why not include it).
A challenging puzzle it was, but good fun!
A challenging puzzle it was, but good fun!