From: paul@paulbmann.com   
      
   >>>start: a   
   >>>a: b 'XX'   
   >>>b: c | '[' b ']'   
   >>>c: 'X' | c 'X'   
   >   
   >> XX is valid, but ambiguous, either a keyword or two X's.   
      
   > Are you sure it is ambiguous?  Maybe it isn't LALR(1), though.   
   > Since there is no a in b or c, it looks to me that it only matches   
   > strings ending in 'XX'.  If b is 'XX' then it still must be followed   
   > by another 'XX'.   
      
   You are right.  I was wrong.   
      
   X  XX is valid   
   XX  XX is valid   
   XXX  XX is valid.   
      
   The parser needs 2 characters of lookahead to correctly   
   parse this language, depending on how spaces are processed.   
      
      
   Paul B Mann   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)