((p|heading|listing|itemize|enumerate|tabular|img|video| slide-show|sql|flowbox|frame|button|next-button|previous-button| back-button|hyperlink|input|scribble|pop-up|browser| multiple-browser|radio-button|checkbox|pull-down| vertical-slider|horizontal-slider|window|page|demo| registration-form|question-form|search-form|shopping-bag| shopping-list|table-of-contents|open|redraw|suspend|close|next| previous|up|down|back|additional|exit|audio|applet|set|empty| non-empty|foreach|order|time-line|on-end-of)+| (par)+)