$\forall$$D$:Dsys, ${\it discrete}$:(Id$\rightarrow$Id$\rightarrow\mathbb{B}$).
\\[0ex]Feasible($D$)
\\[0ex]$\Rightarrow$ d{-}feasible{-}discrete($D$;${\it discrete}$)
\\[0ex]$\Rightarrow$ ($\exists$$w$:World. (PossibleWorld($D$;$w$) \& ($\forall$$i$, $x$:Id. discrete($i$;$x$) = ${\it discrete}$($i$,$x$))))