Kropki: Black kropki dots mark two digits that are in a ratio of 1:2 to each other.
Quadruple: Digits inside the white circles must appear at least once in the surrounding digits.
Entropy: Let the low(123), medium(456) and high(789) digits be three separate groups. Every quadruple that IS NOT marked with a number in the middle must include digits of all three groups. Marked quadruples don't include members of all three groups.
link: https://f-puzzles.com/?id=y77lqpdb
Solution code: column 3 and row 9, no spaces
on 23. March 2022, 13:15 by AParliamentofOwls
@Big Tiger Thank you very much!
on 23. March 2022, 01:02 by Big Tiger
That was a lot of fun. Not difficult, just had to pay attention and slowly whittle things down - and yet very enjoyable to do so.