Display:

$f\circ f^{(-1)}=\mathrm{id}$

Source:

<apply>
     <eq/>
     <apply>
          <compose/>
          <fn>
               <ci> f </ci>
          </fn>
          <apply>
               <inverse/>
               <fn>
                    <ci> f </ci>
               </fn>
          </apply>
     </apply>
     <ident/>
</apply>