Logic Masters Deutschland e.V.

Huzzah, it's been a while there...


My current main project has still been under reconsiderations for a long while, and constant interferences in real life didn't really help further so it's still quite a bummer to not officially publish this one yet. For now, here's a sweet puzzle with an idea I got to incorporate a few days ago, but the entire puzzle was only then refined a few more times before finally reaching my desired thought.


This following puzzle isn't trivial overall, but I hope the logic remain clear and well telegraphed enough till the end for everyone :)


Rules:

- Normal Sudoku rules apply: every row, column and 3x3 box contains digits from 1 to 9 each once.

- Constraints in this puzzle are all standard ones, including: Killer cage, Double arrow (red line with two end circles), German whisper (green line), Palindrome (thicker gray line), Modular (teal line), Kropki dots (both black dot and white dot, but not all such dots are given).



Specific explanation for each constraint:

+ Killer cage: Digits within a cage sum to the small number written in the top left of that cage.
+ Double Arrow: The sum of the digits along the red line that has two circles as its endpoints must equal to the sum of two digits in both circles. It's possible that digits can repeat along a line if allowed by other rules.
+ German Whisper: Along the green line, two adjacent digits have the difference of at least 5.
+ Palindrome: Along the gray palindrome line, digits form a sequence that reads the same as from either endpoint's directions.
+ Modular: Along each teal line, the set of three sequential cells must contain one digit from set {1,4,7}, one digit from set {2,5,8} and one digit from set {3,6,9}.
+ Kropki dots: Two digits connected by a black dot have 1:2 ratio relationship, while two digits connected by a white dot have difference of 1. Not all black dots and white dots are given.



Puzzle:  F-puzzle  -  Penpa plus  -  Sudokupad

Good luck and have fun solving!