Numeroituvat

Numeroituvat refers to a concept in mathematics, particularly in set theory, describing sets whose elements can be put into a one-to-one correspondence with the set of natural numbers. Such sets are also known as countably infinite sets or denumerable sets. This means that even though the set is infinite, its elements can be listed in a sequence, such that every element appears in the list exactly once. The set of natural numbers itself {1, 2, 3, ...} is the archetypal numeroituvat set. Other examples include the set of integers {..., -2, -1, 0, 1, 2, ...} and the set of rational numbers (fractions). The cardinality, or size, of a numeroituvat set is denoted by aleph-null (ℵ₀). It is a fundamental concept for understanding different sizes of infinity. Sets that are not numeroituvat are called uncountably infinite.