Ordered list in the form (x1, x2, …, xn) where xi represent elements of a perfectly defined set.
Examples
- The coordinate pair (2, 5) is an n-tuple of order 2.
- An n-tuple of order 3, such as (2, 5, 7) is called a triplet.
- The next orders are called: quadruplet, quintuplet, sextuplet, etc.
Etymological Note
- The suffix tuple is an extension of the multiplicative suffix –uple or –iple that we find in words like triple, quadruple, quintuple, etc. and in the word duplicate. The Indo-European origin of this suffix means “folded” or “doubled”. Therefore, to quadruple something, we must multiply it by 4.
- The suffix tuple is used for some substantives (nouns) where there is the idea of duplicating or reproducing something. So, an n-tuple of elements is an assembly of n elements in which we can easily distinguish the first, second, … the n-th.