blockBlock2002-03-07 16:04:532002-03-07 16:04:53Definition% this is the default PlanetMath preamble. as your knowledge
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% define commands hereA subgraph $B$ of a graph $G$ is a \emph{block of} $G$ if either it is a bridge (together with the vertices incident with the bridge) or else it is a maximal 2-connected subgraph of $G$.
Any two blocks of a graph $G$ have at most one vertex in common. Also, every vertex belonging to at least two blocks is a cutvertex of $G$, and, conversely, every cutvertex belongs to at least two blocks.
\footnotesize{Adapted with permission of the author from \emph{\PMlinkescapetext{Modern Graph Theory}} by B\'{e}la Bollob\'{a}s, published by Springer-Verlag New York, Inc., 1998.}