Stairway to seven
- XV and number dots
- Arrows
- Whisper lines
- Entropic lines
- Palindromes
The brief
Normal Sudoku rules apply. The orange line is an entropy line, i.e. each set of three consecutive digits on the orange line has to contain a low (1, 2 or 3), a medium (4, 5 and 6) and a high digit (7, 8 or 9). The green lines are German whisper lines, i.e. adjacent digits on a green line have a difference of at least 5. Digits on the grey line form a palindrome, i.e. they read the same forward and backward. Digits on an arrow sum to the digit in the circle from which the arrow emerges. Digits joined by a V sum to 5. Digits joined by an X sum to 10. (Not all V and X are given.)