An Invitation to Alexandrov Geometry: CAT(0) Spaces

mso-fareast-language: EN-US;" From the reviews of the first edition:"In the preface of this book, the authors state a “Manifesto of Alexandrov geometry”, under the slogan “back to Euclid”: Alexandrov geometry may be viewed as a direct generalization of the axiomatic system of Euclid, with some of the equalities changed to inequalities.