  Wigner's argument inferring Bell-type inequality for the EPR-Bohm entangled
state is generalized here for any N-partite state. This is based on assuming
for the relevant dichotomic observables the existence of the overall joint
probability distributions, satisfying the locality condition, that would yield
the measurable marginal probabilities. For any N, such Generalized Wigner's
Inequality (GWI) is violated by quantum mechanics for all pure entangled
states. The efficacy of GWI is probed, comparing with the Seevinck-Svetlichny
multipartite Bell-type inequality, by calculating threshold visibilities for
the quadripartite GHZ, Cluster andWstates that determine their respective
robustness with respect to the quantum mechanical violation of GWI in the
presence of white noise.
