Sciweavers

WG
2009
Springer
14 years 2 months ago
Exact and Parameterized Algorithms for Max Internal Spanning Tree
We consider the NP-hard problem of finding a spanning tree with a maximum number of internal vertices. This problem is a generalization of the famous Hamiltonian Path problem. Our...
Henning Fernau, Serge Gaspers, Daniel Raible
LICS
2009
IEEE
14 years 2 months ago
Dinatural Terms in System F
We provide in this article two characterisation results, describing exactly which terms verify the dinaturality diagram, in Church-style system F and in Curry-style system F. The ...
Joachim De Lataillade
LICS
2009
IEEE
14 years 2 months ago
An Improved Lower Bound for the Complementation of Rabin Automata
Automata on infinite words (ω-automata) have wide applications in formal language theory as well as in modeling and verifying reactive systems. Complementation of ωautomata is ...
Yang Cai, Ting Zhang, Haifeng Luo
LICS
2009
IEEE
14 years 2 months ago
The Complexity of Global Cardinality Constraints
In a constraint satisfaction problem (CSP) the goal is to find an assignment of a given set of variables subject to specified constraints. A global cardinality constraint is an ...
Andrei A. Bulatov, Dániel Marx
LICS
2009
IEEE
14 years 2 months ago
An Exponential Lower Bound for the Parity Game Strategy Improvement Algorithm as We Know it
This paper presents a new lower bound for the discrete strategy improvement algorithm for solving parity games due to V¨oge and Jurdzi´nski. First, we informally show which stru...
Oliver Friedmann
LICS
2009
IEEE
14 years 2 months ago
Wreath Products of Forest Algebras, with Applications to Tree Logics
—We use the recently developed theory of forest algebras to find algebraic characterizations of the languages of unranked trees and forests definable in various logics. These i...
Mikolaj Bojanczyk, Howard Straubing, Igor Walukiew...
LICS
2009
IEEE
14 years 2 months ago
An Algebra for Kripke Polynomial Coalgebras
Several dynamical systems, such as deterministic automata and labelled transition systems, can be described as coalgebras of so-called Kripke polynomial functors, built up from co...
Marcello M. Bonsangue, Jan J. M. M. Rutten, Alexan...
LICS
2009
IEEE
14 years 2 months ago
Logics with Rank Operators
—We introduce extensions of first-order logic (FO) and fixed-point logic (FP) with operators that compute the rank of a definable matrix. These operators are generalizations o...
Anuj Dawar, Martin Grohe, Bjarki Holm, Bastian Lau...