es{-}receives(${\it es}$;$e$;$l$)
\\[0ex]$\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$receives(es{-}eq(${\it es}$);IdLnkDeq;es{-}pred?(${\it es}$);es\_info(${\it es}$);1of(es{-}oaxioms(${\it es}$));$e$;$l$)