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math.CO1998
Mobius functions of lattices
Andreas Blass, Bruce E. Sagan
We introduce the concept of a bounded below set in a lattice. This can be used to give a generalization of Rota's broken circuit theorem to any finite lattice. We then show how thi…
math.CO1998
Characteristic and Ehrhart polynomials
Andreas Blass, Bruce E. Sagan
Let A be a subspace arrangement and let chi(A,t) be the characteristic polynomial of its intersection lattice L(A). We show that if the subspaces in A are taken from L(B_n), where…