Logic Masters Deutschland e.V.

Place each of the digits 1 through 9 once into each row, column, and 3x3 box. Adjacent digits that sum to five are always connected by a V. Adjacent digits that sum to ten are always connected by an X. Adjacent digits that are consecutive are always connected by a white dot.

Negative constraints apply, including that each pair of adjacent digits satisfies at most one of these conditions (since no pair of adjacent digits is connected by two different symbols).

Online solver links: CTC, f-puzzles