Geartrain
(Published on 25. July 2024, 20:42 by DarthParadox)
If you'd like a somewhat easier introduction to these rules, check out Moduloops!
Place the digits 1-9 once into each row, column, and 3x3 box.
XV and Kropki dots work modulo 9:
- Two digits separated by an X must sum to 10.
- Two digits separated by a V must sum to either 5 or 14.
- Two digits separated by a white dot must be consecutive; 1 and 9 are consecutive.
- Two digits separated by a black dot must be in a 1:2 ratio modulo 9, meaning that one digit multiplied by 2 must be equal to either the other digit or the other digit plus 9. For example, 5 and 1 can be separated by a black dot, because 5 x 2 = 10 = 1 + 9.
Online solver: SudokuPad

Solution code: Row 8, left to right
Last changed on on 29. July 2024, 18:59
Solved by SKORP17, kublai, PierreTombal, bansalsaab, filuta, Toomas_, lmdemasi, Snookerfan, zhall12570, asii, Megalobrainiac, atomvic, Dentones, Mikemerin, PippoForte, Bobbobert
Comments
on 29. July 2024, 18:59 by DarthParadox
Added link to Moduloops
on 27. July 2024, 14:08 by Snookerfan
Great puzzle! Thank you
on 26. July 2024, 11:57 by filuta
Great idea and wonderfully implemented.
on 26. July 2024, 11:13 by Toomas_
Brilliant execution of ideas! Thanks for the very nice puzzle :)