1. The notion of maximal projection is adopted from X-bar theory . 2. X-bar theory derives its name from the overbar. 3. X-bar theory , for instance, often sees individual words corresponding to phrasal categories. 4. X-bar theory contends that every noun has a corresponding determiner ( or specifier ). 5. There are three " syntax assembly " rules which form the basis of X-bar theory . 6. The result can be very " tall " trees, such as those associated with X-bar theory . 7. Being a constraint on x-bar theory , the criterion aims to parse out ill-formed sentences. 8. For more complex utterances, different theories of grammar assign X-bar theory elements to phrase types in different ways. 9. In X-bar theory , S-H-C is a primitive, an example of this is Kayne's antisymmetry theory. 10. Originally, X-bar theory used a bar over syntactic units to indicate bar-levels in syntactic structure, generally rendered as an overbar.