@Misc{BagnaraHMZ04EA,
  Author = "R. Bagnara and P. M. Hill and E. Mazzi and E. Zaffanella",
  Title = "Widening Operators for Weakly-Relational Numeric Abstractions",
  Howpublished = "Report {\tt arXiv:cs.PL/0412043}",
  Year = 2004,
  Note = "Extended abstract.
          Contribution to the \emph{International workshop on
          ``Numerical \& Symbolic Abstract Domains''}
          (NSAD'05, Paris, January 21, 2005).
          Available at \url{http://arxiv.org/}
          and \url{http://www.cs.unipr.it/ppl/}",
  Abstract = "We discuss the divergence problems recently identified
              in some extrapolation operators for weakly-relational
              numeric domains. We identify the cause of the
              divergences and point out that resorting to more
              concrete, syntactic domains can be avoided by
              researching suitable algorithms for the elimination of
              redundant constraints in the chosen representation.",
}