Abstract
Recall that the W-hierarchy, defined in terms of Fagin definability, may be viewed as a refinement of NP in the world of parameterized complexity theory, whereas the A-hierarchy, defined in terms of model-checking problems, may be viewed as a parameterized analogue of the polynomial hierarchy. Nevertheless, in this section we shall prove that the first levels of both hierarchies coincide, that is, W[1] = A[1].
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
Rights and permissions
Copyright information
© 2006 Springer-Verlag Berlin Heidelberg
About this chapter
Cite this chapter
(2006). The First Level of the Hierarchies. In: Parameterized Complexity Theory. Texts in Theoretical Computer Science. An EATCS Series. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-29953-X_6
Download citation
DOI: https://doi.org/10.1007/3-540-29953-X_6
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-29952-3
Online ISBN: 978-3-540-29953-0
eBook Packages: Computer ScienceComputer Science (R0)