It is well known that the constraint satisfaction problem over a general
relational structure A is polynomial time equivalent to the constraint problem
over some associated digraph. We present a variant of this construction and
show that the corresponding constraint satisfaction problem is logspace
equivalent to that over A. Moreover, we show that almost all of the commonly
encountered polymorphism properties are held equivalently on the A and the
constructed digraph. As a consequence, the Algebraic CSP dichotomy conjecture
as well as the conjectures characterizing CSPs solvable in logspace and in
nondeterministic logspace are equivalent to their restriction to digraphs.
Structure of relations: algebra and applications; Code: FT120100666
Funder: Natural Sciences and Engineering Research Council of Canada
Complexity in Algebra and Algebra in Complexity: the role of finite semigroups and general algebra; Funder: Australian Research Council (ARC); Code: DP1094578
Computation in direct powers; Funder: Australian Research Council (ARC); Code: P 24285
Mike Behrisch;Edith Vargas-García;Dmitriy Zhuk, 2018, The Number of Clones Determined by Disjunctions of Unary Relations, arXiv (Cornell University), 63, 6, pp. 1298-1313, 10.1007/s00224-018-9905-y, https://arxiv.org/abs/1811.11737.