Today we live in the world which is very much a man-made or artificial. In such a world there are many systems and environments, both real and virtual, which can be very well described by formal models. This creates an opportunity for developing a "synthetic intelligence" - artificial systems which cohabit these environments with human beings and carry out some useful function. In this book we address some aspects of this development in the framework of reinforcement learning, learning how to map sensations to actions, by trial and error from feedback. In some challenging cases, actions may...