I added a few hints below for if you get stuck.
- Standard Sudoku: Place the digits 1-9 once in every row, column, and box.
- German whisper lines: Digits on green lines differ by at least 5.
- Entropic lines: Any set of three sequential cells along a peach line must contain a low digit (1-3), a middle digit (4-6) and a high digit (7-9).
- Kropki dots: Digits seperated by a black dot have a ratio of 2, digits seperated by a white dot have a difference of 1.
Play in sudokupad
hint 1
Using set theory, it can be proven that every digit on an entropic line also appears on the whisper line. That's a lot of 'middle digits' for a whisper line!
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hint 2
Have you tried placing a 3 in box 7?
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hint 3
The set used in hint 1 is not only usefull for the break-in!
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