defn MainWindow:
    Window:
        title = "Html example"
        constraints = [vertical(top, html, bottom),
                        horizontal(left, html, right)]
        Html -> html:
            source = (
                      "<p><b>This text is bold</b></p>"
                      "<p><i>This text is italic</i></p>"
                      "<p><small>This text is small</small></p>"
                      "<p>This is<sub> subscript</sub> and <sup>superscript</sup></p>"
                  )