Anton, I now see that, in Gray, the precedence of "&&" is higher than every   
   other operator.   
      
   So Gray EBNF:   
   a b && c d && e f && <- x   
      
   is equivalent to Wirth EBNF:   
      
   x = a { b a } c { d c } e { f e } .   
      
   Likewise:   
      
   a b && ? <- x   
      
   is   
   x = [ a { b a } ] .   
      
   Carl   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)