anchor.diff:          let grid = makeGrid buildBoundsC
           Seq.fold
               (fun (generatedMap, rand) coordinates ->
  -                let tile = Map.find coordinates originalMap
  -                if  tile <> PathTile &&
  -                    MapBounds.isPointInBounds coordinates buildBoundsC then
  -                    if anAdjacentTileIs coordinates TreeTile buildBoundsC originalMap then 
  -                        let (n, rand) = Rand.nextIntUnder 3 rand
  -                        if n = 0 then (Map.add coordinates TreeTile generatedMap, rand)
  -                        else (generatedMap, Rand.advance rand)
  -                    else (generatedMap, Rand.advance rand)
  +                let (n, rand) = Rand.nextIntUnder 3 rand
  +                if n = 0 && Map.find coordinates originalMap <> PathTile && anAdjacentTileIs coordinates TreeTile buildBoundsC originalMap && MapBounds.isPointInBounds coordinates buildBoundsC
  +                then (Map.add coordinates TreeTile generatedMap, rand)
                   else (generatedMap, Rand.advance rand))
               (generatedMap, rand)
               grid
  
positive.code:             Seq.fold
                  (fun (generatedMap, rand) coordinates ->
                      let (n, rand) = Rand.nextIntUnder 128 rand
                      if alldjacentTilesAre coordinates GrassTile buildBoundsC generatedMap then
                          if n = 0 && Map.find coordinates generatedMap = GrassTile
                          then (Map.add coordinates WaterTile generatedMap, rand)
                          else (generatedMap, rand)
                      else (generatedMap, rand))
                  (generatedMap, rand)
                  grid
  
negative.code:             Seq.fold
                  (fun (generatedMap, rand) coordinates ->
                      let (n, rand) = Rand.nextIntUnder 1 rand
                      if n = 0 && Map.find coordinates generatedMap <> PathTile && anAdjacentTileIs coordinates WaterTile buildBoundsC originalMap
                      then (Map.add coordinates WaterTile generatedMap, rand)
                      else (generatedMap, rand))
                  (generatedMap, rand)
                  grid
  