public TeXFormula add(String s) throws ParseException {
  if (s != null && s.length() != 0) {
    textStyle=null;
    add(new TeXFormula(s));
  }
  return this;
}

public TeXFormula add ( String s ) throws ParseException { if ( s != null && s . length ( ) != 0 ) { textStyle = null ; add ( new TeXFormula ( s ) ) ; } return this ; }
parses the given string and inserts the resulting formula at the end of the current texformula .
