Collections
<#Include Label="[1]{coll}">

IsCollection (Filter)
<#Include Label="IsCollection">

Collection Families
<#Include Label="CollectionsFamily"> <#Include Label="IsCollectionFamily"> <#Include Label="ElementsFamily"> <#Include Label="CategoryCollections">

Lists and Collections
Sorted Lists as Collections
The following functions take a list or collection as argument, and return a corresponding list. They differ in whether or not the result is mutable or immutable (see ), guaranteed to be sorted, or guaranteed to admit list access in constant time (see ).

<#Include Label="IsListOrCollection"> <#Include Label="Enumerator"> <#Include Label="EnumeratorSorted"> <#Include Label="EnumeratorByFunctions"> <#Include Label="List:coll"> <#Include Label="SortedList"> <#Include Label="SSortedList"> <#Include Label="AsList"> <#Include Label="AsSortedList"> <#Include Label="AsSSortedList"> <#Include Label="Elements">

Attributes and Properties for Collections
<#Include Label="IsEmpty"> <#Include Label="IsFinite"> <#Include Label="IsTrivial"> <#Include Label="IsNonTrivial"> <#Include Label="IsWholeFamily"> <#Include Label="Size"> <#Include Label="Representative"> <#Include Label="RepresentativeSmallest">

Operations for Collections
<#Include Label="IsSubset"> <#Include Label="Intersection"> <#Include Label="Union"> <#Include Label="Difference">

Membership Test for Collections
\in
in
returns true if the object obj lies in the collection C, and false otherwise.

The infix version of the command

obj in C

calls the operation , for which methods can be installed.

gap> 13 in Integers; [ 1, 2 ] in Integers; true false gap> g:= Group( (1,2) );; (1,2) in g; (1,2,3) in g; true false
Random Elements
<#Include Label="[2]{coll}"> <#Include Label="Random:coll"> <#Include Label="PseudoRandom"> <#Include Label="RandomList">

Iterators
<#Include Label="Iterator"> <#Include Label="IteratorSorted"> <#Include Label="IsIterator"> <#Include Label="IsDoneIterator"> <#Include Label="NextIterator"> <#Include Label="IteratorList"> <#Include Label="TrivialIterator"> <#Include Label="IteratorByFunctions">