[clean-list] making use of _print_graph

[eli+@gs211.sp.cs.cmu.edu]

Ronny Wichers Schreur wrote:
> This snippet can be used in a module where you don't use the
> layout rule (module header ends with a semicolon). My guess is
> that you do use the layout rule.

So that's it -- I guessed this might be, but my guess involved
removing the curly-braces as well as indenting.  Thank you very much;
with this plus file_to_true ripped from StdDebug I'm much happier
about debugging. 

> You can also have a look at the WrapDebug library
> <http://www.cs.kun.nl/~clean/Download/Download_Libraries/wrapdebug/wrapdebug.html>.

Ah, this is more polished than what I did.

-- 
     Eli Brandt  |  eli+@cs.cmu.edu  |  http://www.cs.cmu.edu/~eli/