Editing Regular graph (section)

{{short description|Graph where each vertex has the same number of neighbors}}
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{{Graph families defined by their automorphisms}}
In [[graph theory]], a '''regular graph''' is a [[Graph (discrete mathematics)|graph]] where each [[Vertex (graph theory)|vertex]] has the same number of neighbors; i.e. every vertex has the same [[Degree (graph theory)|degree]] or valency. A regular [[directed graph]] must also satisfy the stronger condition that the [[indegree]] and [[outdegree]] of each internal vertex are equal to each other.<ref>
{{Cite book | last = Chen | first = Wai-Kai | title = Graph Theory and its Engineering Applications | publisher = World Scientific | year = 1997 | pages = [https://archive.org/details/graphtheoryitsen00chen/page/29 29] | isbn = 978-981-02-1859-1 | url-access = registration | url = https://archive.org/details/graphtheoryitsen00chen/page/29 }}</ref> A regular graph with vertices of degree {{mvar|k}} is called a '''{{nowrap|{{mvar|k}}‑regular}} graph''' or regular graph of degree {{mvar|k}}.

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