$\forall$${\it ds}$:$x$:Id fp$\rightarrow$ Type, ${\it da}$:$k$:Knd fp$\rightarrow$ Type, $i$:Id, ${\it es}$:ES. \\[0ex]($\forall$$x$:Id. vartype($i$;$x$) $\subseteq\rho$ ${\it ds}$($x$)?Top) \\[0ex]$\Rightarrow$ ($\forall$$e$:E. loc($e$) $=$ $i$ $\Rightarrow$ valtype($e$) $\subseteq\rho$ ${\it da}$(kind($e$))?Top) \\[0ex]$\Rightarrow$ ($\forall$$e_{1}$, $e_{2}$:E. loc($e_{2}$) $=$ $i$ $\Rightarrow$ es{-}hist\{i:l\}(${\it es}$;$e_{1}$;$e_{2}$) $\in$ event{-}info(${\it ds}$;${\it da}$) List)