ector.fromList(toList <I>s</I>)</TT>.</P>
    </DD>

    <DT>
      <TT>insert (<I>s</I>, <I>x</I>)</TT> <BR>
      <TT>insertDisjoint (<I>s</I>, <I>x</I>)</TT> <BR>
      <TT>insertWith <I>f</I> (<I>s</I>, <I>x</I>)</TT>
    </DT>
    <DD>
      <P>Returns the set <TT><I>s</I></TT> extended with element
      <TT><I>x</I></TT>. In the first form, if <TT><I>s</I></TT> already
      contains an element <TT><I>y</I></TT> equal to <TT><I>x</I></TT>, then it
      gets replaced by <TT><I>x</I></TT>. In the seco