Nordic Slopes
- Kropki dots
- XV and number dots
- Indexing lines
- Entropy windows
The brief
- Normal sudoku rules apply.
- Global Entropy - every 2 by 2 box of cells has at least one low digit (1,2,3), one medium digit (4,5,6), and one high digit (7,8,9).
- Indexing - on a blue index line, the digit in the Nth cell along the line (starting from the diamond) indicates the position along the line where the digit N appears. Eg: 3214 would be a valid line; the 1st digit, 3, indicates that the 3rd digit is a 1, and so on.
- Ratio Kropki - digits separated by a black Kropki dot have a ratio of 2:1. No negative constraint.
- X pairs - digits separated by X sum to 10. No negative constraint.
