add documentation

edmonds.cpp

@@ -4,6 +4,13 @@ using namespace ED;
 
 namespace Edmonds {
 
+/**
+ * @return List of vertices of the x-r path, where r is the root of the
+ * special blossom forest component x belongs to.
+ *
+ * @note This assumes that the values of μ, φ and ρ represent a special
+ * blossom forest on the graph when this method is called.
+ * **/
 std::vector<NodeId> path_to_forest_root(Graph const & graph, NodeId id)
 {
    std::vector<NodeId> retval;