anchor.diff:  grammar Dcpu;
   
   program
  -    : (label | instruction | data_section)+ EOF
  +    : (label | instruction | dataSection)+ EOF
       ;
   
   label
  
positive.code: STI : 'STI' | 'sti' ;
  STD : 'STD' | 'std' ;
  
  argument_a
      : REGISTER
      | location_in_register
      | location_offset_by_register
      | POP
      | PEEK
      | pick
  
negative.code:     | 'pop'
      ;
  
  argumentB
      : REGISTER
      | locationInRegister
      | locationOffsetByRegister
      | PUSH
      | PEEK
      | pick
  