Logic Masters Deutschland e.V.

THE RULES

Normal sudoku rules apply. Place the digits 1 to 9 in every row, column, and 3x3 box.

Orthogonally adjacent digits that are in a 1/2 ratio are separated by a black dot. ALL black dots are given.

White dots separate consecutive digits and not all white dots are given.

Battenberg rule applies: Orthogonally adjacent digits on the pink and yellow Battenberg cells are opposite parity (odd/even).

“Bat and Berg” rule applies. Within the grid are the black outline of a flying bat and the blue outline of an iceberg largely submerged in box 9 but with its tip protruding into box 6. Adjacent digits along the outlines of the Bat and Berg are opposite parity (odd/even).

The tip of the iceberg is a digit that is one tenth the mass of the total ice berg. The mass of the ice berg is the sum of all digits on and inside the blue outline

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CREDITS:

This puzzle is a whimsical response to Glum Hippo’s “World, A Tuning Fork” that is one of my favorite puzzles, and which I solved without realizing there is a negative constraint, which makes it even nicer. It was my first Battenberg puzzle and I loved the interaction of the odd/even pairs with the odd/even zipper lines. My puzzle does not match the beauty or complexity of that puzzle.

Many thanks to puzzler fajoogaloo who “solved” an earlier version of this puzzle and alerted me to the fact that it was unsolvable, describing in great detail all the ways tried. Fajoogaloo also solved this version of the puzzle and gave feedback, so I am confident this one has a solution and only one solution.

Link to Sven Neumann’s Sudokupad