anchor.diff:  
   
   //-----------------------------------------------------------------
  -
   // SPX Protocol rules.
  -
   // (PROTOCOL = SPX)(SERVICE = spx_service_name)
  -
  -//-----------------------------------------------------------------
  -spx_protocol     : spx_params ; 
  -
  -spx_params       : spx_parameter+ ; 
  +//-----------------------------------------------------------------
  +spx_protocol     : spx_params ;
  +
  +spx_params       : spx_parameter+ ;
   
   spx_parameter    : spx_spx
  -                 | spx_service ; 
  -
  -spx_spx          : L_PAREN PROTOCOL EQUAL SPX R_PAREN ; 
  +                 | spx_service ;
  +
  +spx_spx          : L_PAREN PROTOCOL EQUAL SPX R_PAREN ;
   
   spx_service      : L_PAREN SERVICE EQUAL ID R_PAREN ;
   
  
positive.code: //-----------------------------------------------------------------
  // TCP Protocol rules.
  // (PROTOCOL = TCP)(HOST = hostname)(PORT = portnumber)
  
  //-----------------------------------------------------------------
  tcp_protocol     : tcp_params ;
                   
  
negative.code: 
  // ---------------------------------------------------------------
  // Ok, I know this defines an IP version 4 address, but I haven't
  // got my head around the IPv6 format yet!
  // It seems that an IPv4 address that begins with a zero is octal.
  // With leading "0x" or "0X" it's hexadecimal. Sigh.
  // ---------------------------------------------------------------
  IP               : QUAD DOT QUAD DOT QUAD DOT QUAD+ ;
                   
  YES_NO           : Y E S | N O ;
                   
  