Logic Masters Deutschland e.V.

Normal Sudoku rules apply.
Numbers outside the grid are Sandwich sums.
Numbers outside the grid are Skyscraper clues.
Lines with circles on both ends are Between Lines.
Lines with circles on both ends are Double Arrows.
Purple lines are Renban Lines.
Purple lines are Zipper Lines.

Sandwich sums: The number outside the grid shows the sum of the digits that appear between the 1 and 9 in that row/column.
Skyscraper clues: The number outside the grid shows the number of "buildings" that can be seen from that edge of the grid. "Buildings" have a height equal to the digit in their cell and "taller buildings" obscure the view of "shorter buildings".
Between Lines: The value of digits along between lines fall strictly between the values in the circles on the ends.
Double Arrows: The sum of the digits along the line and the sum of the digits in the two circles is the same.
Renban: Digits along this line are a set of non-repeating, consecutive numbers, in any order.
Zipper: The sum of pairs of digits equidistant from the center of the line is the same for all pairs. On odd length lines, this sum appears in the central cell.

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