Dichotomies for classes of homomorphism problems involving unary functions

@article{Feder2004DichotomiesFC,
title={Dichotomies for classes of homomorphism problems involving unary functions},
author={Tom{\'a}s Feder and Florent R. Madelaine and Iain A. Stewart},
journal={Theor. Comput. Sci.},
year={2004},
volume={314},
pages={1-43}
}

We study non-uniform constraint satisfaction problems where the underlying signature contains constant and function symbols as well as relation symbols. Amongst our results are the following. We establish a dichotomy result for the class of non-uniform constraint satisfaction problems over the signature consisting of one unary function symbol by showing that every such problem is either complete for L, via very restricted logical reductions, or trivial (depending upon whether the template… CONTINUE READING