From: Meyer-Eltz@t-online.de   
      
   >>  (here i want to write a block of statements or rules which will be   
   >>executed if B doesnt match to C/D/E.)   
      
   >>Now, the "modern" parsing methodologies like GLR, PEGs, and   
   >>predicated   
   >>grammars are closed under complement, so if you use a technique like   
   >>that, you can add a NOT rule and still create a parser.   
      
   > I'd appreciate some references.   
      
      
   With TextTransformer   
      
   http://www.texttransformer.com   
      
   you can write a look-ahead production   
      
   B ::= C|D|E   
      
   and then call it in another production like   
      
   IF(!B())   
   block of statements or rules   
   ELSE   
   produce an error or do something else   
   END   
      
   You can immediately try it in the TextTransformer interpreter.   
      
      
   Detlef   
      
   --- SoupGate-Win32 v1.05   
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