#proof systems

It reminds me of eskrima: apparently they teach you defence with knives first before teaching you bare-handed defence. The idea being that if you can defend yourself with knives (which requires more delicacy), then you can defend yourself easily with your bare hands. Just as apparently some magician (I think it was Houdini) practiced card tricks with gloves on in the cold trenches during a world war--and when the war was over, he could do card tricks with his gloves off even better.

This book introduces some basic topics in the spectral theory of dynamical systems, but also includes advanced topics such as a theorem due to H. Helson and W. Parry, and another due to B. Host. Spectral Theory of Dynamical Systems Moreover, Ornstein's family of mixing rank one automorphisms is described with construction and proof. Systems of imprimitivity, and their relevance to ergodic theory, are discussed. Baire category theorems of ergodic theory, scattered in the literature, are derived in a unified way. Riesz products are considered, and they are used to describe the spectral types and eigenvalues of rank one automorphisms. "Spectral Theory of Dynamical Systems" is the first book devoted exclusively to this subject, moving from introductory material to some topics of current research. The exposition is at a general level and aimed at advanced students and researchers in dynamical systems.