($<$o,Id$>$ monoid on $T$) $\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$$<$$T$$\rightarrow$$T$, $\lambda$$x$,$y$. tt, $\lambda$$x$,$y$. tt, $\lambda$$f$,$g$. $f$ o $g$, Id, $\lambda$$x$.$x$$>$