8 search results - page 2 / 2 » The Dichotomy of List Homomorphisms for Digraphs |
DAM
2006
13 years 8 months ago
2006
DAM
2008
13 years 8 months ago
2008
For digraphs D and H, a mapping f : V (D)V (H) is a homomorphism of D to H if uv A(D) implies f(u)f(v) A(H). For a fixed directed or undirected graph H and an input graph D, the...
ICALP
2007
Springer
14 years 2 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...