•S
indexes a discrete set of sites.
–S =
{1, …, m}
–S =
{(i,j) | 1 <= i, j <= n} for nxn grid.
•Ld = discrete set of labels, eg. {1, … M}.
–Labels could be
continuous, but we skip that.
•A labeling assigns
a label to every site,
•f = {f1, … fm}. fi is the label of
site i.