1650 search results - page 1 / 330 » The HOM problem is decidable |
STOC
2010
ACM
14 years 2 months ago
2010
ACM
We close affirmatively a question which has been open for long time: decidability of the HOM problem. The HOM problem consists in determining, given a tree homomorphism D and a re...
CSR
2009
Springer
13 years 11 months ago
2009
Springer
A homomorphism from a graph G to a graph H (in this paper, both simple, undirected graphs) is a mapping f : V (G) → V (H) such that if uv ∈ E(G) then f(u)f(v) ∈ E(H). The pro...
STACS
2010
Springer
13 years 9 months ago
2010
Springer
Abstract. In the constraint satisfaction problem (CSP), the aim is to find an assignment of values to a set of variables subject to specified constraints. In the minimum cost hom...
PODS
2008
ACM
14 years 4 months ago
2008
ACM
Conjunctive query (CQ) evaluation on relational databases is NP-complete in general. Several restrictions, like bounded tree-width and bounded hypertree-width, allow polynomial ti...
CORR
2010
Springer
13 years 1 months ago
2010
Springer
We show that unless P=NP, there exists no polynomial time (or even pseudo-polynomial time) algorithm that can decide whether a multivariate polynomial of degree four (or higher ev...