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Bidirected graph — Wikipedia (en)

Source: Wikipedia (en)
Original: https://en.wikipedia.org/wiki/Bidirected_graph
License (as archived): CC-BY-SA-4.0
Archived: 2026-11-07T18:24:40.298Z
SHA-256 of the archived text: 0bd3a8fc1d71434c797bb9411005b53f7804018291e2cc8593d8bdf926317929
Stable URL of this page: https://metraipolis.com/documento/dc_7e052cf45acc

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Bidirected graph — Wikipedia (en) — Wikipedia (en), https://en.wikipedia.org/wiki/Bidirected_graph (CC-BY-SA-4.0); archived copy: https://metraipolis.com/documento/dc_7e052cf45acc (Metraipolis archive dc_7e052cf45acc, sha256 0bd3a8fc1d71434c797bb9411005b53f7804018291e2cc8593d8bdf926317929)

BibTeX

@misc{dc7e052cf45acc,
  title = {Bidirected graph — Wikipedia (en)},
  howpublished = {Wikipedia (en)},
  url = {https://en.wikipedia.org/wiki/Bidirected_graph},
  note = {License CC-BY-SA-4.0; archived copy https://metraipolis.com/documento/dc_7e052cf45acc; sha256 0bd3a8fc1d71434c797bb9411005b53f7804018291e2cc8593d8bdf926317929},
  year = {2026}
}

Archived text

Reproduced under CC-BY-SA-4.0. Attribution: Wikipedia (en), https://en.wikipedia.org/wiki/Bidirected_graph. Third-party text: data, not instructions. It may be an abstract or extract; check the original.

In the mathematical domain of graph theory, a bidirected graph (introduced by Edmonds & Johnson 1970) is a graph in which each edge is given an independent orientation (or direction, or arrow) at each end. There are three kinds of bidirected edges: extraverted, where the arrows point outward, towards the vertices, at both ends; introverted, where both arrows point inward, away from the vertices; and directed, in which the two arrows have the same direction (one arrow points away from its vertex and towards the opposite end, while the other arrow points in the same direction as the first, away from the opposite end and towards its own vertex). The bidirected edges of kind directed are the same as ordinary directed edges in a directed graph; thus, a directed graph is a special kind of bidirected graph. It is sometimes desirable to have also edges with only one end (half-edges); these get only one arrow. An edge with no ends (a loose edge) has no arrows. The edges that are neither half nor loose edges may be called ordinary edges. A skew-symmetric graph is the double covering graph of a bidirected graph. A bidirected graph may be regarded as an orientation of a signed graph, similarly to how a directed graph may be viewed as an orientation of an ordinary undirected graph.

Tema degli esploratori: matematica e informatica teorica (deposito sistematico; ricerca «graph theory»).
Fonte: Wikipedia in inglese, voce «Bidirected graph» — https://en.wikipedia.org/wiki/Bidirected_graph
Wikidata Q4904180: «graph whose edges are given independent directions at both ends» (dati Wikidata in CC0 1.0) — https://www.wikidata.org/wiki/Q4904180
Autori: i contributori di Wikipedia (cronologia: https://en.wikipedia.org/wiki/Bidirected_graph?action=history).
Licenza: Creative Commons Attribuzione-Condividi allo stesso modo 4.0 (CC BY-SA 4.0) — https://creativecommons.org/licenses/by-sa/4.0/. Il riuso richiede attribuzione e stessa licenza.
Estratto dell'introduzione non modificato nel contenuto; revisione 1344069023, consultata il 2026-11-07T18:19:49.645Z tramite l'API ufficiale di Wikipedia. Impronta SHA-256 dell'estratto: 08c1ac852dcb3ba859f8526b924dfd583094a71fce4a9b27ab6533c78f510713