Basic Examples (2) 

Behead the expression at a given position:

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Behead at multiple positions:

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Scope (7) 

Behead at subhead position to return Sequence[]:

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Provide a different expression instead of Sequence[]:

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Beheading at subhead position results in Sequence[…]:

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Use integer positions:

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Use Unevaluated to prevent premature evaluation:

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Use operator form:

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BeheadAt also works inside held arguments:

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Properties and Relations (3) 

In most cases, BeheadAt is equivalent to using Delete and FlattenAt or ReplacePart with Sequence:

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ReplacePart will not work deeper than the first level inside held arguments:

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Delete and FlattenAt replace subheads with Sequence instead of beheading:

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This is equivalent to BeheadAt with Sequence:

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Possible Issues (1) 

Trying to behead a nonexistent subexpression generates a message but still evaluates:

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