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Electronic Colloquium on Computational Complexity

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All reports by Author Phokion G. Kolaitis:

TR09-033 | 16th April 2009
Phokion G. Kolaitis, Swastik Kopparty

Random Graphs and the Parity Quantifier

The classical zero-one law for first-order logic on random graphs says that for every first-order property $\varphi$ in the theory of graphs and every $p \in (0,1)$, the probability that the random graph $G(n, p)$ satisfies $\varphi$ approaches either $0$ or $1$ as $n$ approaches infinity. It is well known ... more >>>

TR06-160 | 17th December 2006
Tomas Feder, Phokion G. Kolaitis

Closures and dichotomies for quantified constraints

Quantified constraint satisfaction is the generalization of
constraint satisfaction that allows for both universal and existential
quantifiers over constrained variables, instead
of just existential quantifiers.
We study quantified constraint satisfaction problems ${\rm CSP}(Q,S)$, where $Q$ denotes
a pattern of quantifier alternation ending in exists or the set of all possible
more >>>

TR06-094 | 29th July 2006
Parikshit Gopalan, Phokion G. Kolaitis, Elitza Maneva, Christos H. Papadimitriou

The Connectivity of Boolean Satisfiability: Computational and Structural Dichotomies

Revisions: 1

Boolean satisfiability problems are an important benchmark for questions about complexity, algorithms, heuristics and threshold phenomena. Recent work on heuristics, and the satisfiability threshold has centered around the structure and connectivity of the solution space. Motivated by this work, we study structural and connectivity-related properties of the space of solutions ... more >>>

TR05-119 | 15th September 2005
Nadia Creignou, Phokion G. Kolaitis, Bruno Zanuttini

Preferred representations of Boolean relations

We introduce the notion of a plain basis for a co-clone in Post's lattice. Such a basis is a set of relations B such that every constraint C over a relation in the co-clone is logically equivalent to a conjunction of equalities and constraints over B and the same variables ... more >>>

TR00-082 | 17th August 2000
Lefteris Kirousis, Phokion G. Kolaitis

The Complexity of Minimal Satisfiability Problems

Revisions: 2

A dichotomy theorem for a class of decision problems is
a result asserting that certain problems in the class
are solvable in polynomial time, while the rest are NP-complete.
The first remarkable such dichotomy theorem was proved by
T.J. Schaefer in 1978. It concerns the ... more >>>

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