For two (agent muɴ-, CVCCV- + -um- & theme) to pull on something (loc ref -an) in opposition to each other (loc ref), as on a rope, a cane, a piece of meat when a carabao is butchered.
Uminna'innat: focus is on two who persist in pulling something against each other; mun'i'innat: focus is on three or more who pull on something against each other.