namer{-}disjoint($n_{1}$;$n_{2}$;${\it nmr}_{1}$;${\it nmr}_{2}$) $\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$$\forall$$i$:\{0..$n_{1}$$^{-}$\}, $j$:\{0..$n_{2}$$^{-}$\}. $\neg$(${\it nmr}_{1}$($i$) = ${\it nmr}_{2}$($j$) $\in$ Id)