Homotopy Type Theory (paperback)Homotopy type theory is a new branch of mathematics that combines aspects of several different fields in a surprising way. It is based on a recently discovered connection between homotopy theory and type theory. It touches on topics as seemingly distant as the homotopy groups of spheres, the algorithms for type checking, and the definition of weak groupoids. Homotopy type theory offers a new univalent foundation of mathematics, in which a central role