A locally finite point set (such as the set Zn of integral points) gives rise to a lat-tice of polytopes in Euclidean space taking vertices from the given point set. We develop the combinatorial structure of this polytope lattice and derive Euler-type relations for valuations on polytopes using the language of Mo bius inversion. In this context a new family of inversion relations is obtained, thereby generalizing classical relations of Euler, DehnSommerville, and Macdonald. 1999 Academic Press AMS Subject Classification: 52B45; 52B05, 52B20, 52B70, 52A38, 05E25 The essential link between convex geometry and combinatorial theory is the lattice structure of the collection of polyconvex sets; that is, the collec-tion of all finite unions of ...