added a comment

Author: nodename

src/com/nodename/Delaunay/Halfedge.as

@@ -28,6 +28,8 @@ package com.nodename.Delaunay
 public var edge:Edge;
 public var leftRight:LR;
 public var vertex:Vertex;
+
+// the vertex's y-coordinate in the transformed Voronoi space V*
 public var ystar:Number;
 
 public function Halfedge(lock:Class, edge:Edge = null, lr:LR = null)