-lux, vaf. Intentional causativizer.

usage: When appearing after a verb ending in /x/, the first /x/ metathesizes with the vowel, or drops if phonotactic restrictions demand.

This form may be realized one of three ways:
-lux appears on most monosyllabic verbs.
-lu appears on back vowel-classed polysyllabic verbs, or verbs of no harmonic class, and appears in place of -lux when another derivational affix follows.
-li appears on front vowel-classed polysyllabic verbs.

The contrast between -lux and -mod is one of intentionality:
Chuphochuris. He made himself fall down. (NB: ts- + -l = -ch-)
Chuphotsndris. He tripped.