From: gene.ressler@gmail.com   
      
   On Nov 22, 10:20 am, an...@mips.complang.tuwien.ac.at (Anton Ertl)   
   wrote:   
   > Gene  writes:   
   > >Nonterminals that can never derive a terminal string are the   
   > >problem.   
   >   
   > Is it really?  Since they cannot derive a terminal, they have no   
   > influence on the language described by the grammar.  They might just   
   > as well not be there.  Are they really a problem (except for certain   
   > implementation techniques)?   
      
   The algorithm is commonly used to print warnings in parser   
   generators.  Check recent releases of bison, for example.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)