abs{-}S($C$;${\it In}$)($j$,$i$,$e$) $\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$($\uparrow$($e$ $\in_{b}$ ${\it In}$)) c$\wedge$ ((${\it In}$($e$).1) = $<$$j$, $i$$>$ $\in$ (:$C$ $\times$ $C$))