$\forall$$T$:Type, $L$:$T$ List, $P$:(\{$x$:$T$$\mid$ ($x$ $\in$ $L$) \}$\rightarrow$Prop). $\forall$$x$$\in$$L$.$P$($x$) $\Leftrightarrow$ ($\forall$$x$$\in$$L$. $P$($x$))