Noun

(en noun)

(set theory) A finite sequence of terms.

A tuple''' is not merely a totally-ordered set because the same element can appear more than once in a '''tuple''': for example, $(a,\; b,\; a)$ qualifies as a 3-'''tuple whereas it would not qualify as a totally-ordered set (of cardinality 3), because the set would be $\backslash \{a,\; b\backslash \}$ where $a\; \backslash le\; b$ and $b\; \backslash le\; a$ so that $a\; =\; b$; i.e., it would actually be a one-element set, $\backslash \{a\backslash \}$, not even just two-element.

If commutativity were added to a tuple, it would turn into a multiset or "bag". For example, words (of some alphabetic language) can be considered to be tuples of letters. If the ordering requirement on those letters were lifted, then the word would become a multiset of letters equivalent to those of its anagrams.

(computing) A single row in a relational database.

(computing) A set of comma-separated values passed to a program or operating system as a parameter to a function call.

(computing) In some programming languages, a data type which is similar but distinct from the list data type, whose instances are characterized by having a rather fixed arity, and the elements of which instances can differ from each other by data type. (Note : this definition may overlap with the previous one.)

Both Python and Haskell have a tuple data type as well as a list data type.

Unlike lists, tuples are not formed by consing.

Noun

(en noun)

A set of two elements treated as one; a pair.

* {{quote-book, year=1908, author=W. D. Ross, title=, by=Aristotle

, passage=... positing a dyad and constructing the infinite out of great and small, instead of treating the infinite as one, is peculiar to him; ...}}

(music) any set of two different pitch classes.

A pair of things standing in particular relation; dyadic relation.

* "For each individual in a specific dyad (i.e., mother-offspring, offspring-father, sibling-sibling),..." Debra Lieberman, John Tooby, and Leda Cosmides - The evolution of human incest avoidance mechanisms: an evolutionary psychological approach , p. 20

(chemistry) An element, atom, or radical having a valence or combining power of two.