index(${\it dE}$; ${\it dL}$; ${\it pred?}$; ${\it info}$; $p$; $r$)
\\[0ex]$\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$mu(($\lambda$$i$.eqof(${\it dE}$)($r$,receives(${\it dE}$; ${\it dL}$; ${\it pred?}$; ${\it info}$; $p$; sender($r$); link($r$))[$i$])))