diff --git a/Data/Graph/AStar.hs b/Data/Graph/AStar.hs
--- a/Data/Graph/AStar.hs
+++ b/Data/Graph/AStar.hs
@@ -64,10 +64,11 @@
          -> (a -> a -> c) -- ^ Distance function between neighbouring vertices of the graph. This will
                           -- never be applied to vertices that are not neighbours, so may be undefined
                           -- on pairs that are not neighbours in the graph.
-         -> (a -> c)      -- ^ Heuristic distance to the (nearest) goal.
+         -> (a -> c)      -- ^ Heuristic distance to the (nearest) goal. This should never overestimate the
+                          -- distance, or else the path found may not be minimal.
          -> (a -> Bool)   -- ^ The goal, specified as a boolean predicate on vertices.
          -> a             -- ^ The vertex to start searching from.
-         -> Maybe [a]     -- ^ An optimal path, if any path exists.
+         -> Maybe [a]     -- ^ An optimal path, if any path exists. This excludes the starting vertex.
 aStar graph dist heur goal start
     = let s = runAStar graph dist heur goal start
       in case end s of
@@ -75,9 +76,13 @@
             Just e  -> Just (reverse . takeWhile (not . (== start)) . iterate (cameFrom s !) $ e)
 
 plane :: (Integer, Integer) -> Set (Integer, Integer)
-plane (x,y) = Set.fromList [(x-1,y),(x+1,y),(x,y-1),(x,y+1),(x-1,y-1),(x+1,y+1),(x-1,y+1),(x+1,y-1)]
+plane (x,y) = Set.fromList [(x-1,y),(x+1,y),(x,y-1),(x,y+1)]
 
+planeHole :: (Integer, Integer) -> Set (Integer, Integer)
+planeHole (x,y) = Set.filter (\(u,v) -> planeDist (u,v) (0,0) > 10) (plane (x,y))
+
 planeDist :: (Integer, Integer) -> (Integer, Integer) -> Double
 planeDist (x1,y1) (x2,y2) = sqrt ((x1'-x2')^2 + (y1'-y2')^2)
     where [x1',y1',x2',y2'] = map fromInteger [x1,y1,x2,y2]
+
 
diff --git a/astar.cabal b/astar.cabal
--- a/astar.cabal
+++ b/astar.cabal
@@ -1,5 +1,5 @@
 name:                astar
-version:             0.0
+version:             0.1
 synopsis:            General A* search algorithm.
 description:         This is a data-structure independent implementation of A* search.
 category:            Data