Useful examples of {nei} are somewhat hard to produce. As selbri or even seltau it is essentially useless, because the result is recursive; this is the case for 6.14. Even as sumti it's not that common, in my experience, to need {lo SE nei} and be unable to use both {vo'V} and {ri}, since this means you need nesting and a nested bridi with > 2 sumti in it.