  The Grishukhin inequality Gr_7 is a facet of CutP_7, the cut polytope on
seven points, which is ``sporadic'' in the sense that its proper generalization
has not been known. In this paper, we extend Gr_7 to an inequality I(G,H) valid
for CutP_{n+1} where G and H are graphs with n nodes satisfying certain
conditions, and prove a necessary and sufficient condition for I(G,H) to be a
facet. This result combined with the triangular elimination theorem of Avis,
Imai, Ito and Sasaki settles Collins and Gisin's conjecture in quantum theory
affirmatively: the I_{mm22} Bell inequality is a facet of the correlation
polytope CorP(K_{m,m}) of the complete bipartite graph K_{m,m} for all m>=1. We
also extend the Gr_8 facet inequality of CutP_8 to an inequality I'(G,H,C)
valid for CutP_{n+2}, and provide a sufficient condition for I'(G,H,C) to be a
facet.
