This video, https://www.youtube.com/watch?v=Xs-88vVnv-E&list=PL6BsSDLnXCAP8ZEgeVENr5gCx6wBmfqZO&index=7, can also be seen at https://www.youtube.com/playlist?list=PL6BsSDLnXCAP8ZEgeVENr5gCx6wBmfqZO.