$\forall$${\it es}$:ES, ${\it Sys}$:AbsInterface(Top), ${\it chain}$:(E(${\it Sys}$)$\rightarrow$(Id List)).
\\[0ex]chain{-}config(${\it es}$;${\it Sys}$;${\it chain}$) $\Rightarrow$ chain{-}config(${\it es}$;${\it Sys}$;($\lambda$$l$.rev($l$)) o ${\it chain}$)