fact: Definition glue2_rel (u v : glue2_vertex) := match u,v with | inl u, inl v => u -- v | inr u, inr v => val u -- val v | inl u, inr v => (u == x) && x' -- val v || (u == y) && y' -- val v | inr v, inl u => (u == x) && x' -- val v || (u == y) && y' -- val v end.
imports: mathcomp(all_ssreflect) GraphTheory(edone preliminaries digraph sgraph) GraphTheory(connectivity minor treewidth arc set_tac)