Clones of partial functions on finite sets

This thesis covers parts of the theory of multiple-valued logics which belongs to discrete mathematics as well as Universal Algebra. Multiple-valued logics deals with functions with finite domains and finite images, and relations on finite sets. These two topics are strongly connected and it has proven fruitful to use the theory on one of them to proceed on the other one. We have to state more accurately what are the objects we deal with and what are the questions connected to them we want to answer.