From: borucki.andrzej@gmail.com   
      
   The simplest this case is grammar :   
   A -> A   
      
   but I have   
      
   A -> B   
   A -> b B   
   B -> A   
   B -> a A   
      
   it is trap for sequence generator. A->B->A->B->A....   
   How detect similar cases, especially without computing First and Follow sets ?   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)