* @return True, if the contents of this statement list changed.
		 */
		public boolean removeAll(final Collection c) {
			boolean changed = false;

			if (c == this) {
				changed = size() > 0;
				clear();
			} else {
				final Iterator iter = c.iterator();

				while (iter.hasNext()) {
					changed = remove(iter.next()) || changed;
				}
			}

			return changed;
		}