Another ML project question...

[liquid_cool]

Ok, at first I asked about doing graphics in ML, I thought the rest would be easy once I learned ML. But I'm discovering it's harder to think in completely recursive way that is required for ML... I understand recursion no problem, but it seems like in ML there can only be one expression per function, so everything has to be recursive and such...
I'm having trouble making an ML program that does Lindenmayer systems. I thought I had it at first, but it seems very complicated considering I've been told it should only take a few lines... plus I couldn't figure out a simple way to change the coordinates and direction of the drawing device at the main function call level.
If anyone could give me some suggestions on the best way to do Lindenmayer Systems (L-systems) in ML, preferably SML/NJ (SML-97) I'd appreciate it alot!