Pro-sumti: references a previously mentioned sumti, but which one is not specified.
Like "zo'e", but its set of possible referents is restricted to only the set of all aforementioned sumti. This is useful in riddles, jokes, and other circumstances when revealing the exact referent is disadvantageous; also, it can be useful in translations of words like "it", "he", "she", and "they" when the translator is not sure of the original pronouns' referents. Each usage updates (meaning that distinct usages of this word can refer to mutually different sumti and any additional new sumti which appears between them can be a referent of the second but not the first "ko'o'e"). Pragmatically, the probability of sumti x being the intended referent decreases dramatically unless x was rather recently mentioned. See also: "ri", "ko'a", "ko'o'au".