To reply to David Yetter's "not being entirely negative", I myself suspected that the matrix notation with special nodes for over/undercrossings (such as \HonV and \VonH) would extend to braids and the like. Maybe those who consider them to be so important conceptually would spend a few minutes thinking out how to express braids in a matrix notation ... BTW I can't readily quote you or edit my own text, because I'm working on a dumb terminal 500km from home. The over and undercrossings of horizontal and vertical lines have been in my package for ages. There's also some kind of "break" feature in xypic. If you care to look in the international TeX archive, you will find macro packages intended for drawing Feynmann diagrams and trees. There are also prototypes of mine for proof trees and natural deduction proof boxes, and many other things. No one package is ever going to do all of the jobs, and nor should it: if you want wysiwyg, use a pen an paper. Paul +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++