Technical Report: Algorithms for Concept Lattice Decomposition and their Applications

We present algorithms for horizontal decomposition, subdirect decomposition, and subtensorial decomposition of concept lattices. The implementations of these algorithms are described and their complexity is investigated. We then apply the decomposition algorithms to reengineering problems in software engineering and present several examples. It turns out that concept lattice decomposition is useful not only for understanding old software, but also for restructuring it.