Abstract
We give a short combinatorial proof of the Euler relation for convex polytopes in the context of oriented matroids. Using counting arguments we derive from the Euler relation several identities holding in the lattice of flats of an oriented matroid. These identities are proven for any matroid by Möbius inversion.
Similar content being viewed by others
Bibliography
Bland, R., Las Vergnas, M.: ‘Orientability of Matroids’, J. Combinatorial Theory (B) 24 (1978), 94–123.
Brugesser, H., and Mani, P.: ‘Shellable Decompositions of Cells and Spheres’, Math. Scand. 29 (1971), 197–205.
Crapo, H. H.: ‘Möbius Inversion in Lattices’, Archiv der Math. 19 (1968), 595–607.
Edmonds, J., and Mandel, A.: (abstract), Notices Amer. Math. Soc. 25 (1978), A-510.
Edmonds, J., Fukuda, K., and Mandel, A.: ‘Topology of Oriented Matroids’, in preparation.
Folkman, J., and Lawrence, J.: ‘Oriented Matroids’, J. Combinatorial Theory (B) 25 (1978), 199–236.
Grünbaum, B.: Convex polytopes, Interscience Publishers, London, New York, Sidney, 1967.
Hadwiger, H.: ‘Eulers Charakteristik und kombinatorische Geometrie’, J. reine angew. Math. 194 (1955), 87–94.
Klee, V.: ‘The Euler Characteristic in Combinatorial Geometry’, Amer. Math. Monthly 70 (1963), 119–127.
Las Vergnas, M.: ‘Convexity in Oriented Matroids’, J. Combinatorial Theory (B) 29 (1980), 231–243, announced in: Matroides orientables. C. R. Acad. Sci. Paris (A) 280 (1975), 61–64.
Las Vergnas, M.: ‘Acyclic and Totally Cyclic Orientations of Combinatorial Geometries’, Discrete Math. 20 (1977), 51–61.
Las Vergnas, M.: ‘Sur les activités des orientations d'une géométrie combinatoire’, Proc. Colloq. Mathématiques Discrètes: Codes et Hypergraphes (Bruxelles 1978), Cahiers C. E. R. O. (Bruxelles) 20 (1978), 293–300.
Las Vergnas, M.: ‘On the Tutte Polynomial of a Morphism of Matroids’, Proc. Joint Canada-France Combinatorial Colloquium, Montréal 1979, Annals Discrete Math. 8 (1980), 7–20.
Lindström, B.: ‘On the Realization of Convex Polytopes, Euler's Formula and Möbius Functions’, Aeq. Math. 6 (1971), 235–240.
Rota, G.-C.: ‘On the Foundations of Combinatorial Theory. I: Theory of Möbius Functions’, Z. Für Wahrscheinlichkeitstheorie und verw. Gebiete 2 (1964), 340–368.
Rota, G-C.: ‘On the Combinatorics of Euler Characteristic’, Studies in Pure Mathematics (presented to Richard Rado), Academic Press, London, 1971, pp. 221–233.
Stanley, R. P.: ‘Modular Elements of Geometric Lattices’, Algebra Universalis 1 (1971), 214–217.
Stanley, R. P.: ‘Combinatorial Reciprocity Theorems’, Advances in Math. 14 (1974), 194–253.
Tverberg, H.: ‘How to Cut a Convex Polytope into Simplices’, Geom. Dedicata 3 (1974), 239–240.
Welsh, D. J. A.: Matroid Theory, Academic Press, London, 1976.
Zaslavsky, T.: ‘Facing up to Arrangements: Face-Count Formulas for Partitions of Spaces by Hyperplanes’, Memoirs Amer. Math. Soc. 154 (1975).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Cordovil, R., Las Vergnas, M. & Mandel, A. Euler's relation, möbius functions and matroid identities. Geom Dedicata 12, 147–162 (1982). https://doi.org/10.1007/BF00147634
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00147634