$\forall$$A$:Type, $B_{1}$, $B_{2}$:($A$$\rightarrow$Type). ($\forall$$a$:$A$. $B_{1}$($a$) $\subseteq\rho$ $B_{2}$($a$)) $\Rightarrow$ $a$:$A$ fp$\rightarrow$ $B_{1}$($a$) $\subseteq\rho$ $a$:$A$ fp$\rightarrow$ $B_{2}$($a$)