15. The method of claim 11 , wherein said estimating the similarity value is based on comparing indexes of the language-independent semantic structures (LISS's) of the sets of source sentences.
15. The method of claim 11 , wherein said estimating the similarity value is based on comparing indexes of the language-independent semantic structures (LISS's) of the sets of source sentences. 19. The method of claim 15 , wherein the indexes of the language-independent semantic structures (LISS's) of the set of source sentences includes indexes of semantic features.