# Caccetta-Häggkvist

## Seymour's Second Neighbourhood Conjecture ★★★

Author(s): Seymour

**Conjecture**Any oriented graph has a vertex whose outdegree is at most its second outdegree.

Keywords: Caccetta-Häggkvist; neighbourhood; second; Seymour

Author(s): Seymour

Keywords: Caccetta-Häggkvist; neighbourhood; second; Seymour

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