anchor.diff:  
           let internal atPoint point node =
               Math.isPointInBounds point node.Bounds
  -
  -        let internal inBounds bounds node =
  -            Math.isBoundsInBounds bounds node.Bounds
   
           let internal intersectingBounds bounds node =
               Math.isBoundsIntersectingBounds bounds node.Bounds
  
positive.code:             if omnipresent then 
                  tree.OmnipresentElements.Remove element |> ignore
              else
                  if not (SpatialNode.inBounds bounds tree.Node) then
                      Log.info "Element is beyond spatial tree's containment area or is not present for removal."
                      tree.OmnipresentElements.Remove element |> ignore
                  else SpatialNode.removeElement bounds element tree.Node
      
  
negative.code:             if omnipresent then 
                  tree.OmnipresentElements.Add element |> ignore
              else
                  if not (SpatialNode.intersectingBounds bounds tree.Node) then
                      Log.info "Element is outside spatial tree's containment area or is being added redundantly."
                      tree.OmnipresentElements.Add element |> ignore
                  else SpatialNode.addElement bounds element tree.Node
  
  