@inbook {IOPORT.05248036,
    author       = {Van Nieuwenborgh, Davy and Heymans, Stijn and Vermeir, Dirk},
    title        = {Cooperating answer set programming.},
    year         = {2006},
    booktitle    = {Logic programming. 22nd international conference, ICLP 2006, Seattle, WA, USA, August 17--20, 2006. Proceedings},
    isbn         = {978-3-540-36635-5},
    pages        = {226-241},
    publisher    = {Berlin: Springer},
    doi          = {10.1007/11799573_18},
    abstract     = {Summary: We present a formalism for logic program cooperation based on the answer set semantics. The system consists of independent logic programs that are connected via a sequential communication channel. When presented with an input set of literals from its predecessor, a logic program computes its output as an answer set of itself, enriched with the input. It turns out that the communication strategy makes the system quite expressive: essentially a sequence of a fixed number of programs $n$ captures the complexity class ${{\Sigma^P}_{n}}$, i.e. the $n$-th level of the polynomial hierarchy. On the other hand, unbounded sequences capture the polynomial hierarchy $\mathcal{PH}$. These results make the formalism suitable for complex applications such as hierarchical decision making and preference-based diagnosis on ordered theories. In addition, such systems can be realized by implementing an appropriate control strategy on top of existing solvers such as dlv or smodels, possibly in a distributed environment.},
    identifier   = {05248036},
}