if ${\it nms}_{1}$ and ${\it nms}_{2}$ overlap then $x$ else $y$ fi
\\[0ex]$\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$if $p$:l\_disjoint(MaName;${\it nms}_{1}$;${\it nms}_{2}$) then $y$ else $x$ fi