The structure of functions = 函数结构 /

　　this book is mainly based on the results of the author and his co-workers ob-tained in the last few years. we tried to present the material in such a way that the main ideas can be understood independently of the existing literature. on the other hand， after proving in chapter i that the function spaces introduced via quarkonial decompositions coincide with the well-established spaces b8pq and fspq we feel free to use known results about these spaces， especially when we have nothing new to say about the assertions used. a reader who is mostly interested in the material presented in one of the chapters ii， iii， or iv， which are largely independent of each other， may skip chapter i， at the first glance.but most of the related proofs in these chapters depend substantially on the theory developed in the first chapter. 　　it is a pleasure to acknowledge the great help i have received from my col-laborators in jena， in particular dorothee haroske and winfried sickel， who made valuable suggestions which have been incorporated in the text. i am especially indebted to dorothee haroske for producing all the figures in this book. last， but not least， i wish to thank my friend and colleague david edmunds in brighton who looked through the whole manuscript and offered many comments.