DocumentationMathematicaBuiltin FunctionsLists and MatricesList Testing
Further Examples: FreeQ
Here is a feature of FreeQ that is absent from MemberQ: FreeQ recognizes that the sum a+c is a subexpression of the larger sum.
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Here we see how the level argument to FreeQ affects its result. When no level is specified, matches at any level are reported.
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The default level specification of FreeQ is . (MemberQ's is .)
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The default for the Heads option of FreeQ is True.
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This gives True since except for the head, this expression is free of ww.
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See also the Further Examples for the Heads option.
