and <TT>existsEq</TT>.
      The index of each pair of elemente (starting from 0) is passed to <TT><I>f</I></TT>
      as an additional argument. The following equivalence hold:</P>
      <PRE>
        allEq <I>f</I> (<I>l1</I>, <I>l2</I>)    = alliEq (<I>f</I> o <I>g</I>) (<I>l1</I>, <I>l2</I>)
        existsEq <I>f</I> (<I>l1</I>, <I>l2</I>) = existsiEq (<I>f</I> o <I>g</I>) (<I>l1</I>, <I>l2</I>)</PRE>
      <P>where</P>
      <PRE>
        <I>g</I> = fn (<I>i</I>,<I>a</I>,<I>b</I>) => <I>f</I>(<I>a</I>,