$\forall$$A$:Realizer, $i$, $x$:Id, $T$:Type, $L$:Knd List.
\\[0ex]R{-}Feasible($A$) $\Rightarrow$ $\neg$$x$ $\in$ dom(R{-}state($A$;$i$)) $\Rightarrow$ @$i$ only events in $L$ change $x$:$T$ $\parallel$ $A$