"Diagonal Stripes and Blocks"
A return of the Primal kropki rules first used in this puzzle:
https://logic-masters.de/Raetselportal/Raetsel/zeigen.php?id=000SGV
Place the digits 1-9 once each in every row and column of the grid.
Primal Kropki: A black dot between two cells indicates that one of the numbers in those cells is exactly double the other. A white dot between two cells indicates that the two numbers in those cells are consecutive. A purple "primer" dot between two cells indicates that either both cells contain a prime number, or neither cell contains a prime number. Not all possible Kropki dots are given.
Sudokupad link: https://sudokupad.app/vo5vnogdya
Solution code: Row 1
on 26. May 2026, 20:11 by dzamie
Very pretty puzzle!
on 25. May 2026, 10:19 by Sudokujoker
Thanks for the feedback - and I like DiMono's idea of being able to prove it in the puzzle!
The definition is that a prime number is any integer with exactly two factors (itself and one), which excludes 1 because it only has one factor (one). But I shouldn't have assumed that everyone knows that specific definition :)