Logic Masters Deutschland e.V.

Rules:

-Normal Sudoku Rules Apply.
-Digits along an arrow must sum to the number in the attached circle. For clarification involving box 7, r789c2 is one arrow and r8c12/r7c3 is another arrow.
-Clues outside the grid give the sum of the arrow circles in the corresponding row/column. The "10-22" and "1-14" clues mean the sum is between (but not including) the endpoints. For the purposes of this constraint, r9c5 is considered an arrow circle.
-In addition, they are also X-Sums clues - they give the sum of the first X digits in that row/column, where X is the digit nearest to the clue. With clues that are not of a specific value, the arrow circle sum and the X-Sums sum must satisfy the inequality/range but they do not necessary have to be equal to each other.
-An inequality sign points to the smaller digit of the two cells it connects.

Links:

F-Puzzles
CTC