The publication of this volume at this time appears particularly auspi cious. Biological, psychological, and social change is greater during the pubertal years than at any other period since infancy. While the past two decades have witnessed a virtual explosion of productive research on the first years of life, until recently research on adolescence, and particularly on puberty and early adolescence, has lagged substantially behind. This book provides encouraging evidence that things are changing for the better. Considered separately, the individual chapters in this book include important...

This book should be accessible to students who have had a first course in matrix theory. The existence and uniqueness theorem of Chapter 4 requires the implicit function theorem, but we give a self-contained constructive proof ofthat theorem. The reader willing to accept the implicit function theorem can read the book without an advanced calculus background. Chapter 8 uses the Moore-Penrose pseudo-inverse, but is accessible to students who have facility with matrices. Exercises are placed at those points in the text where they are relevant. For U. S. universities, we intend for the book to be...

On becoming familiar with difference equations and their close re lation to differential equations, I was in hopes that the theory of difference equations could be brought completely abreast with that for ordinary differential equations. HUGH L. TURRITTIN, My Mathematical Expectations, Springer Lecture Notes 312 (page 10), 1973] A major task of mathematics today is to harmonize the continuous and the discrete, to include them in one comprehensive mathematics, and to eliminate obscurity from both. E. T. BELL, Men of Mathematics, Simon and Schuster, New York (page 13/14), 1937] The theory of...

This book should be accessible to students who have had a first course in matrix theory. The existence and uniqueness theorem of Chapter 4 requires the implicit function theorem, but we give a self-contained constructive proof ofthat theorem. The reader willing to accept the implicit function theorem can read the book without an advanced calculus background. Chapter 8 uses the Moore-Penrose pseudo-inverse, but is accessible to students who have facility with matrices. Exercises are placed at those points in the text where they are relevant. For U. S. universities, we intend for the book to be...

The publication of this volume at this time appears particularly auspi- cious. Biological, psychological, and social change is greater during the pubertal years than at any other period since infancy. While the past two decades have witnessed a virtual explosion of productive research on the first years of life, until recently research on adolescence, and particularly on puberty and early adolescence, has lagged substantially behind. This book provides encouraging evidence that things are changing for the better. Considered separately, the individual chapters in this book include important...