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
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We study the computational complexity of counting the fixed point configurations (FPs), the predecessor configurations and the ancestor configurations in certain classes of graph or network automata viewed as discrete dynamical systems. Early results of this investigation are presented in two recent ECCC reports [39, 40]. In particular, it is ... more >>>

We give an answer to the question of Barrington, Beigel and Rudich, asked in 1992, concerning the largest n such that the OR function of n variable can be weakly represented by a quadratic polynomial modulo 6. More specially,we show that no 11-variable quadratic polynomial exists that is congruent to ... more >>>