anchor.diff:  guard: 'guard' '()' '{' bstr '}' { obj->set_guard($3.str); }
       | { obj->empty_guard(); } ;
   
  -implicit_guard: bstr { obj->set_guard($0.str); };
  -
   body: ('body'|'model') '()' '{' bstr '}' { obj->set_body($3.str); }
       | { obj->empty_body(); };
   
  
positive.code: }
  }
  
  aal: aal_start header+ ( act | tag | itag | comment )* '}' ;
  
  aal_start: 'aal' string '{' language {
              obj->set_namestr($1.str);
  
negative.code:         } ;
  
  tag: 'tag' tstr '{' comment* guard  comment* '}' { obj->next_tag(); };
  
  tstr:   string          {
              obj->set_tagname($0.str);
  