Аннотация:The article illustrates some of the salient features of Government Phonology (GP) 2.0 by axiomatising (a subclass of) the set of possible Putonghua forms.We show that a phonological theory can profit by assuming that phonological representations are hierarchical, just like syntactic representations. A structural relation of c++command, a relative of the well-known c-command, is used heavily. The similarity with syntax is further underlined by the introduction of a phonological Binding Theory: illicit representations are prohibited by the LUxI Principles, the phonological counterpart of Principles A, B and C.