public static PathImpl lookup(String url){
  PathImpl pwd=getPwd();
  if (!url.startsWith("/")) {
    return pwd.lookup(url,null);
  }
 else {
    return PWD.lookup(url,null);
  }
}

public static PathImpl lookup ( String url ) { PathImpl pwd = getPwd ( ) ; if ( ! url . startsWith ( "/" ) ) { return pwd . lookup ( url , null ) ; } else { return PWD . lookup ( url , null ) ; } }
returns a new path relative to the current directory .
