Machinarium is a puzzle adventure game with a lot of interesting puzzles, some of which are amenable to constraint programming. The first in game sub-puzzle you face is three interlocking circles in a triangle shape. The goal is to move the circles left and right until all the greens form an equilateral triangle.
This puzzle is similar to the river cross puzzle. However, board has the cosmetic additions of ; for line endings and . for spaces. Also here we demonstrate that you don't need to state the object explicitly, an implicit declaration works as well.
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