THIS IS DOCUMENTATION FOR AN OBSOLETE PRODUCT.
SEE THE DOCUMENTATION CENTER FOR THE LATEST INFORMATION.

DOCUMENTATION CENTER SEARCH

Mathematica > Core Language > Expressions > Expression Structure > Level >

BUILT-IN MATHEMATICA SYMBOL

Level

gives a list of all subexpressions of expr on levels specified by levelspec.

applies f to the sequence of subexpressions.

With the option setting Heads->True, Level includes heads of expressions, and their parts.

Level traverses expressions in depth-first order, so that the subexpressions in the final list are ordered lexicographically by their indices.

Give all parts at level -1:

Give all parts down to level 2:

Give all parts at levels 0 through infinity:

Give all parts at level -1:

Out[1]=

Give all parts down to level 2:

Out[1]=

Give all parts at levels 0 through infinity:

Out[1]=

Down successive numbers of levels:

Negative levels:

Ranges of levels:

Use different heads at each level:

Including heads:

Find the leaf elements in an expression:

Include heads:

Find unique leaf expressions:

Level always lists parts in the lexicographic order of their indices:

Level by default starts at level 1, so it does not include the whole expression: