A nice little article. But I think it misses a noteworthy issue. > Context-sensitive languages are something that you will rarely encounter during “normal” pro

A nice little article. But I think it misses a noteworthy issue. > Context-sensitive languages are something that you will rarely encounter during “normal” programming. In my experience, context-sensitive languages, as a class, are never encountered in programming. Certainly, one might need to deal with a formal language that happens to be context-sensitive but not context-free; however, the fact that it lies in the context-sensitive class does not ever seem to be a useful fact. The concepts of regular, context-free, and recursively-enumerable languages are obviously useful ones for us. But I think the only reason programmers ever mention the class of context-sensitive languages is that they feel obligated to, having mentioned the other three classes in Chomsky's hierarchy. If anyone knows of an instance where the fact the concept of context-sensitive languages/grammars was useful in a computational context[1], I'd like to hear about it. [1] Heck, any context. Are context-sensitive grammars really useful in the study of natural languages? I wouldn't be surprised if the answer turns out to be "no".