ИСТИНА

Joint work with Ivanov-Pogodaev, We use geometric methods for the construction. We assign elements of the semigroup by paths on a special metric space. This space can be considered as aperiodic tiling by finite number of tiles. The relations in the semigroup can be assigned by flips on this tiling. Using these assignments we can transform a given word and obtain some area in which this word's path can be situated. Using some monomial relations we obtain that all words with big powers can be reduced to nil. Unlike the classical group situation, our complex is non-planar.