$\forall$$T$:Type, $r$:($T$$\rightarrow$$T$$\rightarrow\mathbb{P}$). irrefl($T$;$r$) $\Rightarrow$ st\_anti\_sym($T$;$r$) $\Rightarrow$ ((($r$$^{\circ}$)$\backslash$) $\Lleftarrow\!\Rrightarrow$\{$T$\} $r$)