Logic Masters Deutschland e.V.

Four problems where the usual line rules apply not to the digits, but to the sums of digits on line segments (with the exception of the last, where the rule applies to digits as well as the line segment sums).

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Normal 4x4 Sudoku rules (all puzzles): Place the digits 1-4 once each into every row, column and 2x2 box.

In each puzzle, lines are divided into segments by box borders and the digits summed on each segment.

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Regionometer (grey line) - segment sums increase from one end of the line to the other.

Region German Whispers (green line): adjacent segments' sums differ by at least 5. N.B. The two diagonal lines in box 3 cross over each other and represent distinct segments.

Region Nabner (gold lines): any pair of segment sums on the same line differ by at least 2.

Parity and Region parity (red line): each pair of adjacent digits contains one odd and one even number, as do each pair of adjacent segment sums.

Modular and Region Modular (teal line): each group of three adjacent digits, when divided by three, results in one each of the numbers 0, 1 and 2 as remainders, as do each group of three adjacent line segments.