| Autor: |
Nathan Linial, Charles Payan, François Jaeger, Michael Tarsi |
| Rok vydání: |
1992 |
| Předmět: |
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| Zdroj: |
Journal of Combinatorial Theory, Series B. 56(2):165-182 |
| ISSN: |
0095-8956 |
| DOI: |
10.1016/0095-8956(92)90016-q |
| Popis: |
Let G = (V, E) be a digraph and f a mapping from E into an Abelian group A. Associated with f is its boundary ∂f, a mapping from V to A, defined by ∂f(x) = Σe leaving xf(e)−Σe entering xf(e). We say that G is A-connected if for every b: V → A with Σx ∈ Vb(x)=0 there is an f: E → A − {0} with b = ∂f. This concept is closely related to the theory of nowhere-zero flows and is being studied here in light of that theory. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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