The concrete syntax used here is not so sophisticated as that by Bernd, but we hope that it is readable (please do not think that it is a proposal, we wouldn't support it ;-). Anyway, we defined macros for most of the used constructs of the abstract syntax, so if you find the example unreadable, it should be not too difficult to customize the latex source for your preferred concrete syntax.
[Sorry: Hyperlatex doesn't like the array environment, so I'm having to omit an example here. See the DVI or Postscript versions, which include it.]