$\forall$${\it es}$:ES, $l_{1}$, $l_{2}$:IdLnk, ${\it tg}_{1}$, ${\it tg}_{2}$:Id. es{-}responsive(${\it es}$;$l_{1}$;${\it tg}_{1}$;$l_{2}$;${\it tg}_{2}$) $\in$ Prop