The Algebra of Flows in Graphs
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David G Wagner
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Article
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1998
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Elsevier Science
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English
โ 452 KB
We define a contravariant functor K from the category of finite graphs and graph morphisms to the category of finitely generated graded abelian groups and homomorphisms. For a graph X, an abelian group B, and a nonnegative integer j, ลฝ j ลฝ . . an element of Hom K X , B is a coherent family of B-valu