Tile invariants: new horizons
Let T be a finite set of tiles. The group of invariants G(T), introduced by Pak (Trans. AMS 352 (2000) 5525), is a group of linear relations between the number of copies of tiles in tilings of the same region. We survey known results about G, the height function approach, the local move property, various applications and special cases. (C) 2002 Elsevier B.V. All rights reserved.
tile invariants height function polyomino tilings conway group undecidability