IsMaxIdeal($r$;$m$) $\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$$\forall$$u$:$\mid$$r$$\mid$. ($\neg$($m$($u$))) $\Leftarrow\!\Rightarrow$ ($\exists$$v$:$\mid$$r$$\mid$. ($m$(($u$ $\ast$ $v$) +$r$ ({-}$r$(1)))))