49 search results - page 3 / 10 » Constraints, Graphs, Algebra, Logic, and Complexity |
ICALP
2007
Springer
14 years 1 months ago
2007
Springer
We present algebraic conditions on constraint languages Γ that ensure the hardness of the constraint satisfaction problem CSP(Γ) for complexity classes L, NL, P, NP and ModpL. Th...
LICS
2002
IEEE
14 years 11 days ago
2002
IEEE
We study relations on trees defined by first-order constraints over a vocabulary that includes the tree extension relation Ì Ì ¼, holding if and only if every branch of Ì ex...
SIAMDM
2010
13 years 5 months ago
2010
For a fixed graph H, let Ret(H) denote the problem of deciding whether a given input graph is retractable to H. We classify the complexity of Ret(H) when H is a graph (with loops ...
CP
2007
Springer
13 years 11 months ago
2007
Springer
Abstract. Computing the minimal network (or minimal CSP) representation of a given set of constraints over the Point Algebra (PA) is a fundamental reasoning problem. In this paper ...
CIE
2006
Springer
13 years 11 months ago
2006
Springer
Abstract. Graph isomorphism (GI) is one of the few remaining problems in NP whose complexity status couldn't be solved by classifying it as being either NP-complete or solvabl...