A Note on Obstructions to Clustered Planarity

Jamie Sneddon, Paul Bonnington


A planar digraph $D$ is clustered planar if in some planar embedding of $D$ we have at each vertex the in-arcs occurring sequentially in the local rotation. By supplementing the operations used to form the usual minors in Kuratowski's theorem, clustered planar digraphs are characterised.

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