From: DrDiettrich1@aol.com   
      
   psaffrey@googlemail.com wrote:   
      
   > I'm trying to build a parser for chemical equations such as   
   >   
   > A + B -> C   
   >   
   > and   
   >   
   > A + B <-> C + D   
   >   
   > I'm using the Python lex/yacc tool ply and at the moment I seem to be   
   > struggling a little. I have done this before, but it was ages ago and   
   > I'm rusty :(   
      
   If you have problems, try to use existing grammars for equivalent   
   languages. In your case a calculator or expression example might be   
   helpful, where you can substitute multiplication and division by your   
   reaction symbols.   
      
   DoDi   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)