Logic Masters Deutschland e.V.

Part of the Negative Lines Series

Here is a document giving some theorems which can help visualize the grid, along with a solve path, hints, and explanations.

Being a 6x6 grid, the filled in parts make A# chord on a guitar, hence the puzzle name, which is also an homage to Saves the Day's song "A Drag in D Flat".

Resist any urges to bifurcate!!! There is logic to solve the puzzle without it, however if you do end up bifurcating there is still a satisfying disambiguation once you finish pencil marking in the entire grid :) Either way, after solving feel free to restart and try it the other way to get the full experience!

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Normal Sudoku rules apply.

Renban: for numbers 2-5, box N's cells all have orthogonal straight lines N long, which have consecutive digits in any order, can overlap, and all lines are given.

I've included an example image below to help visualize this rule.

Minimum: the dot's digit is less than its orthogonally adjacent cells.

For clarification: top row boxes are 123, bottom are 456. Additionally all letters outside the grid are just for show.

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Solve in Sudokupad (includes solution) or F-Puzzles


Example Cell

This ruleset is similar to a Kropki puzzle with a negative constraint, where if "all dots are given" and none are in the grid, adjacent cells cannot be consecutive or be in a 2:1 ratio.

Here is an example of all the "missing" lines that would pass through R5C2. This is also in the document link above.