I have posted a new version of Graph Based Logic and Sketches, by Atish Bagchi and Charles Wells, here: http://www.cwru.edu/artsci/math/wells/pub/pdf/gbls.pdf This will eventually appear on ArXiv. -- Charles Wells professional website: http://www.cwru.edu/artsci/math/wells/home.html blog: http://www.gyregimble.blogspot.com/ abstract math website: http://www.abstractmath.org/MM//MMIntro.htm personal website: http://www.abstractmath.org/Personal/index.html