$\forall$$T$:Type, $L$:$T$ List, $R$:(\{$x$:$T$$\mid$ ($x$ $\in$ $L$) \}$\rightarrow$Realizer), $x$:$T$.
\\[0ex]($\forall$$x$$\in$$L$. R{-}Feasible($R$($x$)))
\\[0ex]$\Rightarrow$ ($\forall$$x$:$T$. Dec(($x$ $\in$ $L$)))
\\[0ex]$\Rightarrow$ ($\forall$$x$, $y$:$T$. ($x$ $\in$ $L$) $\Rightarrow$ ($y$ $\in$ $L$) $\Rightarrow$ $R$($x$) $\parallel$ $R$($y$))
\\[0ex]$\Rightarrow$ ($x$ $\in$ $L$)
\\[0ex]$\Rightarrow$ [[$R$($x$)]] $\subseteq$ [[$\oplus$$x$$\in$$L$.$R$($x$)]]