$\forall$$A$:Type, $B$:($A$$\rightarrow$Type), $f$:$a$:$A$ fp$\rightarrow$ $B$($a$), ${\it eq}$:EqDecider($A$), $x$:$A$. $x$ $\in$ dom($f$) $\Rightarrow$ $f$($x$) $\in$ $B$($x$)