I looked at the gallery, and the topics on the forum, and the Linux man page.
I see how to lay out objects on a grid (I think I understand that). Is it possible to request that lines are only horizontal and vertical?
I don’t object to crossing lines. The diagrams I want to construct have two meanings for crossing lines: They cross without touching, or they are connected where they cross. Where they are connected, there’s a tiny circle. I need to be able to specify the difference. If I can specify zero-size nodes (as well as tiny circles), that would be workable because the graphviz program would be output from another program.
There’s an example at http://vandyke.mynetgear.com/1401/docs/ALD/4_7/722348.pdf. Is this possible (preferably easy) with graphviz? If so, what should I read?