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Heads

is an option for functions which use level specifications that specifies whether heads of expressions should be included.

Details
Details and Options Details and Options
Examples  
Basic Examples  
Scope  
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Heads

Heads

is an option for functions which use level specifications that specifies whether heads of expressions should be included.

Details

  • Heads->True treats heads just like other elements of expressions for the purpose of levels.
  • Heads->False never includes heads as part of any level of an expression.
  • Most functions which use level specifications have the default setting Heads->False. One exception is Position, for which the default is Heads->True.

Examples

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Basic Examples  (1)

Scope  (2)

Map f also onto the head:

Parts inside heads are included if appropriate level specifications are given:

Wolfram Research (1991), Heads, Wolfram Language function, https://reference.wolfram.com/language/ref/Heads.html.

Text

Wolfram Research (1991), Heads, Wolfram Language function, https://reference.wolfram.com/language/ref/Heads.html.

CMS

Wolfram Language. 1991. "Heads." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/Heads.html.

APA

Wolfram Language. (1991). Heads. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Heads.html

BibTeX

@misc{reference.wolfram_2025_heads, author="Wolfram Research", title="{Heads}", year="1991", howpublished="\url{https://reference.wolfram.com/language/ref/Heads.html}", note=[Accessed: 14-August-2025]}

BibLaTeX

@online{reference.wolfram_2025_heads, organization={Wolfram Research}, title={Heads}, year={1991}, url={https://reference.wolfram.com/language/ref/Heads.html}, note=[Accessed: 14-August-2025]}