This is documentation for Mathematica 8, which was
based on an earlier version of the Wolfram Language.
View current documentation (Version 11.2)
Structural Operations on Expressions
Mathematica's unified symbolic architecture immediately allows it to perform structural transformations not only on objects like lists, but also on general symbolic expressions that can represent concrete or abstract data of any kind.
Flatten flatten out nested functions (associativity)
Thread thread a function over lists or other constructs
Sort sort elements of an expression (commutativity)
FlattenAt flatten particular elements
Distribute apply distributivity to nested functions
Reverse  ▪ Transpose  ▪ Outer
Join join expressions together
Append  ▪ Prepend  ▪ Take  ▪ Drop
Part([[...]] ▪ ReplacePart  ▪ MapAt  ▪ ...
Head-Related Operations