Creates a predicate abstraction sumti out of a full bridi clause, binding all the necessary lambda variables to the ko'a-ko'u pronoun series. The number of bound variables must be indicated by appending {xi} followed by that number to the word {fo'ai}, unless only one variable (namely {fo'a}) is bound, in which case the {xi} marking is optional.
Number suffix initiating a subordinate clause representing a predicate whose arity is the suffixed number; the lambda variables representing the predicate slots are bound from the fo'a-fo'u series in their dictionary ordering; the number of bound variables is the same as the predicate arity.