$\vdash$  $\forall$$T$:Type, $E$:($T$$\rightarrow$$T$$\rightarrow\mathbb{P}$). ($\downarrow$EquivRel($T$;$x$,$y$.$E$($x$,$y$))) $\Rightarrow$ EquivRel($T$;$x$,$y$.$\downarrow$$E$($x$,$y$))