es{-}p{-}locl(${\it es}$;$p$;$e$;${\it e'}$) $\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$$\exists$$n$:$\mathbb{N}^{+}$. (p{-}graph(es{-}E(${\it es}$);$p$\^{}$n$)(${\it e'}$,$e$))