It is highly recommended you view the pdf available here: attachment:diffraction-JohnstonTarjan.pdf Altervatively, you can view an html version [wiki:Self:DougJohnston/DiffractionJohnstonTarjan online here] Or you can see the page with the animations and slightly better formatting if I do say so myself :P http://www.paulisageek.com/school/cs348b/