The Correlations of Greenberger-Horne-Zeilinger States Described by   Hilbert-Schmidt decomposition
  Using simple quantum analysis we describe the correlations of Greenberger-Horne-Zeilinger (GHZ) states by the use of Hilbert-Schmidt (HS) representation. Our conclusion is that while these states disprove local-realism they do not prove any nonlocality property. 
Y.Ben-Aryeh