Some of you may already have noticed, i'm working on stuff for Tia's Elementary Program.
There is a system behind this, basicaly enabling us to combine different track behaviours for "ZX"-plane (= the top view) and "YL" (= height by length) while at the same time independently controlling these behaviours.
tiny & preliminary description: http://tinyurl.com/adveg
I've put up some pics to give you ideas / irritation / impatience for what to expect. These pics are from equations working reliably already. (please also read descriptions).
http://nldc.interfix.net/p577
Finaly some actual stuff to play with:
http://tinyurl.com/cvrnn
have fun, redunzelizer