Graph minor
= Graph minor
{title2=$H\preccurlyeq G$}
{wiki}
A graph minor is obtained by deleting <vertices>, deleting <edges>, and performing <edge contractions>. Equivalently, its <vertices> can be represented by disjoint nonempty connected sets of <vertices> in the original <graph>, with an <edge> joining two sets whenever the corresponding <vertices> are adjacent. These are <branch sets of a graph minor>.