This book deals with the symbiotic relationship between the theory of function spaces, fractal geometry, and spectral theory of (fractal) pseudodifferential operators. It investigates distributions of eigenvalues of fractal (pseudo)differential operators.

This volume covers Lebesgue integration and its generalizations from Daniell's point of view, modified by the use of seminorms. The integration of functions, as opposed to the measuring of sets, is posited as the main purpose of measure theory.