Hello, I'm still playing with Attempto. It takes several day to learn how we have to writea sentence. So I have some trouble with word chaining. It won't work. For instance : "There is a list of tree" must be rewrite like " There is a tree's list." because the first does'nt works. But how can I write : "There is a list of tree of comments." ? "There is a comment's tree's list." ? It won't works of course. So I could split the sentence : "A thread is a tree of comment. There is a list of thread." But when I want to express very common concept like : "An agent may know the person's date of birth." it's difficult to split the sentence. So, is there another solution ? Regards, Pierre-Alex -- --------------------- Isaac Project - <a href="http://www.lisaac.org/">http://www.lisaac.org/</a>