I have a directed graph $G$ , with some set of nodes $R$.
For this set of nodes $r \in R$, I ask whether all nodes link to a given node $n$ not belonging to $R$. That is I ask if from each of nodes $r \in R$ there exists an edge $e(r,n)$ linking node of our path with node $n$.
1) How can we name such relation between set of nodes $R$ and node $n$.
2) In case of multigraph, where there can be more than one edge $e(r,n)$ How can we enumerate through such .. 'connections' , 'cuts' ?
What rings a bell form me is a:
- clique
- cycle
- cut
but I cannot find a proper definitons for this. Thanks in advance
For the first question: a star? http://mathworld.wolfram.com/StarGraph.html