This value is necessary to be consistent with the recursive definition of what a product over a sequence means.
The idea that recursion is an essential property of human language (as Chomsky suggests) is challenged by linguist Daniel Everett in his work Cultural Constraints on Grammar and Cognition in Pirahã: Another Look at the Design Features of Human Language, in which he hypothesizes that cultural factors made recursion unnecessary in the development of the Pirahã language.
Recursion: the results of one search could be used in subsequent queries.
In Matter, the Morthanveld Nestworld of Syaung-un is a "Sphere World" consisting of a complex, recursive arrangement of transparent tubes within tubes within tubes, all revolving around a small central star.
Recursion | Walther recursion | recursion | Kleene's recursion theorem | BCFW recursion |
Fixed-point combinators, which are used in lambda calculus for the same purpose as the first recursion theorem.
# A restricted form of recursion, which operates only upon ‘reduced’ forms of its arguments, such as Walther recursion, substructural recursion, or "strongly normalizing" as proven by abstract interpretation of code.