eger value <I>i</I> into a term.
        <LI><TT>`+(<I>x</I>,<I>y</I>)</TT> denotes the sum
            of <I>x</I> and <I>y</I>.
        <LI><TT>`-(<I>x</I>,<I>y</I>)</TT> denotes
            the difference of <I>x</I> and <I>y</I>.
        <LI><TT>`*(<I>x</I>,<I>y</I>)</TT> denotes the
            product of <I>x</I> and <I>y</I>.
      </UL>
      <P></P>
    </DD>

    <DT>
      <TT>datatype rel =<BR>
	  &nbsp;&nbsp;&nbsp;&nbsp;`&lt;&nbsp;&nbsp;&nbsp;of term * term<BR>
	  &nbsp;&nbsp;| `&lt;=&nbsp;&nbs