In page-$13$ of [Graph minors. $X$. Obstructions to tree-decomposition](http://www.sciencedirect.com/science/article/pii/009589569190061N), $\gamma(G)$ introduced as maximum size of an edge. What is the definition of size of an edge$?$ I think it may be number of edges that incident on terminals of an edge.



What is the definition of size of an edge$?$
At the beginning of the section in the paper they let $G$ be a *hypergraph*. The size of a (hyper)edge is the number of vertices it contains.


