As can be seen in Tables 2 and 3, a lower frequency induces a more limited paradigmatic modifiability for a particular sel (which is, of course, expressed as a higher probability value; see the column labeled mod sel in both tables).
with s being the number of distinct possible selections for a particular k, the k-modifiability, mod k , of an n-gram can be defined as follows (f stands for frequency): The paradigmatic modifiability, P -M od, of an ngram is the product of all its k-modifiabilities: Comparing the trigram P -M od values for k = 1, 2 in Tables 2 and 3, it can be seen that the term "long terminal repeat" gets a much higher weight than the non-term "t cell response", although their mere frequency values suggest the opposite.