This is a book of two minds. It is, on one hand, a book on technique, and technique is, undoubtedly, its raison d'être. Topics and examples have often been chosen for no other reason than their illustrative value for some aspect of the differentiability techniques.
But the book aslo uses technique as an excuse for a systematic, although not exhaustive, account of some of the central topics of general equilibrium theory. In other words, it is one of the objectives of this book to reexamine the theory of general economic equilibrium from the differentiable point of view.