It is not possible to design a complementary counterpart for each labyrinth. The complementary is obtained by horizontally mirroring of the pattern whilst the connections between the entrance, the center and their corresponding circuits in the labyrinth are left uninterrupted. If the entrance and the access to the center are situated on the same side of the axis, this does not work.
Fig. 1 shows this with the example of the alternating, one-arm labyrinth with 6 circuits and the sequence of circuits 3 2 1 6 5 4. As can be seen from the pattern (figure in the middle), the entrance and the access to the center are situated on the same side of the axis. The pathway first leads to the 3rd cricuit and finally reaches the center from the 4th circuit. If we want to mirror this pattern and let the connections with the entrance and the center unbroken, then the lines intersect at the position marked with a black circle. Such a figure is not free of crossroads any more and thus no labyrinth. In alternating labyrinths with an even number of cirucits, therefore, there exist no complementary labyrinths.
Now there are also non-alternating labyrinths with an even number of circuits in which the entrance to the labyrinth and the access to the center lie on the opposite sides of the axis. The labyrinth shown in fig. 2 is such an example and has already been repeatedly discussed in this blog.
This non-alternating, one-arm labyrinth with 6 circuits has the sequence of circuits 3 2 1-6 5 4. That is the same sequence of cirucits as in labyrinth shown in fig. 1 with the difference, that the pathway traverses the axis between circuit 1 and 6. So we are here presented a labyrinth with an even number of circuits, but with the entrance and access to the center on the opposite sides of the axis. Despite this, it is not possible to form a complementary labyrinth to this. If we mirror the pattern vertically without interrupting the connections with the entrance and the center, this results in two crossroads (highlighted with black circles).
Thus, complementary counterparts can only be found in alternating labyrinths with an odd number of circuits.