olemus
ISO/IEC 29128:
funktsiooni omadus, mis seisneb ta muutuvas aarsuses
= property of a function whose arity is variable

ülevaateid
https://en.wikipedia.org/wiki/Variadic_function
https://gobyexample.com/variadic-functions
https://projecteuclid.org/journals/notre-dame-journal-of-formal-logic/volume-54/issue-1/The-First-Order-Syntax-of-Variadic-Functions/10.1215/00294527-1731380.pdf