anchor.diff:     ;
   
   describedecl
  -   : '@describe' stringliteral 'as' expression
  +   : '@describe' property 'as' expression
      ;
   
   contentsdecl
  
positive.code:    | noteditdecl
     | createdecl
     | editdecl
     ;
  
  programdecl
  
negative.code: 
  editdecl
     : '@edit' property
     ;
  
  addaliasdecl
     : '@addalias' name (',' name)* 'to' expression
     ;
  
  statement
  