Discovery revisited
![[Maple Metafile]](images/TR41.gif)
![[Maple Metafile]](images/TR42.gif)
![[Maple Metafile]](images/TR43.gif)
![[Maple Metafile]](images/TR44.gif)
![[Maple Metafile]](images/TR45.gif){kind=small}
![[Maple Metafile]](images/TR46.gif)