n-tuple

$n$-tuple

An $n$-tuple is an ordered list of length $n$.

$$a_1,a_2,\dots a_n\in A:(a_1,a_2,\dots a_n)$$

Ordered $⟹$ $(a,b)\ne (b,a)$, as opposed to sets $\{a,b\}=\{b,a\}$

Pair

A pair is an $n$-tuple with $n=2$:

$$a,b\in A:(a,b)$$

Alternative notation I came across $(a:b)$