An indexed family is a collection of objects that are indexed by some indices. They are denoted as \{A_i\}_{i\in I} .


Let S be a set. Let I be a set.

Then, a family of elements of S indexed by elements of I is a mapping a:I\to S .

I is called the indexing set.


The image of an element of I is denoted as S_i .

That is, a(i)=S_i .

A a family of elements of S indexed by I is denoted as \{S_i\}_{i\in I} . If the indexing set is known, they may be denoted as \{S_i\} .

Ad blocker interference detected!

Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.