 
  
  
  
  
 
Alternative formal definitions are possible.
An interesting possibility is to view the specification
as a ``true rendering'', and actual renderings as
demoted forms of this true rendering. With this
approach, the true rendering   is simply
the specification,
  is simply
the specification,
  
 
  
 
  
 
 
  
  
  
  
 | Jeff Tupper | March 1996 |