anchor.diff:     ;
   
   
  +DSEG
  +   : D S E G
  +   ;
  +
  +
  +CSEG
  +   : C S E G
  +   ;
  +
  +
   REP
      : R E P
      ;
  
positive.code:    ;
  
  line
     : (assemblerdirective | instruction)? comment?
     ;
  
  instruction
     : lbl? prefix? opcode expressionlist?
     ;
  
  lbl
     : label ':'
     ;
  
  prefix
  
negative.code:    ;
  
  org
     : ORG name
     ;
  
  title
  