The book studies boundary value problems connected with geometric singularities and models of the crack theory. New and interesting phenomena on the behaviour of solutions (regularity in weighted spaces, asymptotics) are analysed by means of parametrices obtained by inverting corresponding scalar and operator-valued symbols. Compared with other expositions in the field of crack theory and analysis on configurations with singularities the present book systematically develops for the first time an approach in terms of algebras of (pseudo-differential) boundary value problems. The calculus is...