The current version of the CDL specification
http://www.w3.org/TR/2004/WD-ws-cdl-10-20040427/	  has an empty
section for an example.
 
I think it is right and proper to have example fragments to accompany each
significant item in the specification to illustrate the correct use of the
syntax and its meaning (and perhaps also to warn against potential mis-use
or mis-application).  It would also be very helpful to have a complete,
though relatively straightforward example to illustrate a complete
description.  I suggest this is added as an Appendix rather than a main
section.
 
The primer could take the structure of developing from scratch, and a stated
scenario, a complete example description.
 
I suggest that the primer is aimed at two complementary functions.
Firstly illustrating how to develop a complete description from first
principles as the group started to do in the 11-13 May 2004 face to face
meeting.
Secondly providing guidance and illustrative uses of all the language
features - elements, attributes and functions, and anything else of
importance.  This may necessitate some extra example fragments over and
above the main example (as the main example should not be made more
complicated or contorted than necessary just to squeeze everything into it.