We may represent a subsignature of that signature as a string of 0s and ls (a Boolean string b, of the form {0,1}*, abbreviated bk) indicating whether (or not) the ith suffix is contained in the subsignature.
if a stem t occurs [t] times, then the probability that it occurs without a particular suffix~ is (1 -prob(fi))[tJ; the probability that it occurs without all of the suffixes missing from the particular subsignature b = {bk} is i-i(1 --bk)(1 -prob(fi)) [t]; k and the probability that the particular subsignature b will arise at all is the sum of those values over all of the stems in the signature: all that is necessary is to estimate the hidden parameters of the frequencies of the individual suffixes in the entire paradigm.