Addenum to the presentation "escwidth-cs06-sli.pdf"
This talk is the original place where the "elimination-ordering" definition
of width of digraphs has been presented,
before the paper of Hunter and Kreutzer at SODA 2007.
Currently (end 2006), we know that Theorem 2.1 (of this slides) still has a hole in a
proof, and Conjecture 3.2 has been proved false by Hunter and Kreutzer.