er may be unable to decide whether to <i>shift</i> 
      (read another symbol) or <i>reduce</i> (replace the recognized right 
      hand side of a production with its left hand side).  This is called a 
      <i>shift/reduce conflict</i>.  Similarly, the parser may not be able 
      to decide between reduction with two different productions.  This is 
      called a <i>reduce/reduce conflict</i>.  Normally, if one or more of 
      these conflicts occur, parser generation is aborted.  However, in 
      