anchor.diff:  argument
      : number
      | dollar
  +   | ques
      | register
      | name
      | string
  
positive.code:     ;
  
  grossrawassemblerdirective
      : PUT  | IF | ENDIF | ORG
      ;
  
  dollar
     : DOLLAR
     ;
  
  register
     : REGISTER
     ;
  
negative.code:    ;
  
  label
     : name | gross
     ;
  
  expression
  