9. A method according to claim 2 including the step of storing an indication in association with the words in the low frequency file, of whether the words are principal and/or participating words in limited semantic compounds.
9. A method according to claim 2 including the step of storing an indication in association with the words in the low frequency file, of whether the words are principal and/or participating words in limited semantic compounds. 10. A method, according to claim 9, wherein a separate file is stored containing limited semantic numbers for each principal word, the limited semantic numbers indicating all participating words, the limited semantic numbers of participating words being attached to the principal words in the same sequence in which the participating words form compound expressions with the principal word.