•Neighborhood specifies dependencies.
–N = {Ni | for all i in S}
–Ni is neighborhood of i. j in
Ni means i and j are neighbors.
•A site is not its own neighbor.
•Neighborhood is symmetric.
•Neighborhood -> conditional indep.
–F is an MRF on
S
w.r.t. N iff:
•P(f) > 0
•P(fi | fS-{i}) = P(fi | fNi)
•