[pstricks] How to do Braids with ps-tricks

[Felix Hoffmann]

Hello everyone,

I am working on a diploma thesis in pure maths, which will need to 
display some braids (not the ones, which are already implemented in 
xyPic). They should look like that:

o    o     o
  |     |      |
  |     |      |
   \  /        |
    x         |
  /   \        |
|      |       |
o    o     o

But cool and not like the one I drew. I am always amazed from the 
things, that are possible with ps-tricks, I guess that there is a 
solution, but I don't know it yet. Of course it should be displayable 
which part of the braid is on top of the other and vice versa. Most 
appreciated would be a version, where I only tell the command which 
braid parts to change in what manner.
Greetings,

Felix from Bonn, Germany