Detail #141: Combining Inverse Number Systems with Another System

The Inverse Number System is a typological oddity, apparently restricted to one family of languages. For slightly more information on it, read wikipedia's entry on grammatical number.

Could this be combined with some other number system? Certainly. However, there's a slight caveat - we can't really decide which system to use on the basis of which number is being marked (since that gets a bit circular and also undoes the effect entirely), deciding it based on gender also seems to undo the effect (or at least, one gender then has to have some kind of subclass system).

However, we could have some case marking follow an inverse number system. One case that might work very well for that could be the instrumental, for instance, and another imaginably good case for it could maybe be the absolutive.

So:

		singular	dual	plural
abs	I	-	-s	-s
	II	-s	-	-s
	III	-s	-s	-
	mass	-s	N/A	N/A
erg	I	-in	-il	-il
	II	-in	-ir	-il
	III	-in	-ir	-il
	mass	-i(n)	N/A	N/A
dat	I	-ek	-wel	-wel
	II	-ek	-wer	-wel
	III	-ek	-wer	-wel
	mass	-ek	N/A	N/A
loc	I	-ku	-kul	-kul
	II	-ku	-kur	-kul
	III	-ku	-kur	-kul
	mass	-kul

Another possibility would be to have the inverse system apply to definite forms, or to have definite articles' congruence go by an inverse system (but not the nouns themselves).