Compression of the condition lattice based on the class context and the extent context

Formal decision context is a formal context with condition attributes and decision attributes, it is a generalization of formal context. For a weakly consistent formal decision context, we propose two methods to compress the condition lattice based on two new formal contexts, M-T class context and M-T extent context, respectively. These two compression methods are both based on decision lattice, and they can simplify the knowledge of the weakly consistent formal decision context so that people can understand its structure and knowledge clearly for a huge formal decision context.