Numeroitavissa
Numeroitavissa is a Finnish mathematical term meaning “countable” or “enumerable.” It describes a set that can be put into a one-to-one correspondence with the natural numbers. More formally, a set S is numeroitavissa if there exists a bijection f: N -> S. From this definition follows that a numeroitavissa joukko on joko äärellinen tai numeroitavan ääretön. Finite sets are trivially numeroitavissa, since they can be matched with a finite initial segment of N. An infinite numeroitavissa set can be listed in a sequence, even though the listing continues without end.
Examples and non-examples are central to understanding the concept. The set of natural numbers N, the set
In a broader context, numeroitavissa is tied to the study of cardinality and the distinction between finite,