anchor.diff:        (
            F_HexDigit+
         )?
  -   ) -> type(IPV6_ADDRESS), popMode
  +   ) -> type ( IPV6_ADDRESS ), popMode
  +;
  +
  +M_NEIGHBOR_IPV6_PREFIX
  +:
  +   (
  +      (
  +         '::'
  +         (
  +            (
  +               F_HexDigit+ ':'
  +            )* F_HexDigit+
  +         )?
  +      )
  +      |
  +      (
  +         F_HexDigit+ ':' ':'?
  +      )+
  +      (
  +         F_HexDigit+
  +      )? '/' F_DecByte
  +   ) -> type ( IPV6_PREFIX ), popMode
   ;
   
   M_NEIGHBOR_NEWLINE
  
positive.code: 
  ALWAYS_COMPARE_MED
  :
  	'always-compare-med'
  ;
  
  ANY
  
negative.code: 
  BOTH
  :
     'both'
  ;
  
  BRIDGE
  