Undefined
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Undefined
Details
- Computations like ConditionalExpression[expr,False] generate Undefined.
- If Undefined appears in an argument of a mathematical function, equation, inequality, or Boolean operator the result will be Undefined.
Examples
Basic Examples (2)Summary of the most common use cases
ConditionalExpression with False condition evaluates to Undefined:
In[1]:=1
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https://wolfram.com/xid/0j49asrs-fqpgp
Out[1]=1
The number of solutions depends on the value of x:
In[1]:=1
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https://wolfram.com/xid/0j49asrs-gw8zus
Out[1]=1
For x=1 only the first solution is defined:
In[2]:=2
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https://wolfram.com/xid/0j49asrs-ivi095
Out[2]=2
Mathematical expressions containing Undefined evaluate to Undefined:
In[3]:=3
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https://wolfram.com/xid/0j49asrs-hv991b
Out[3]=3
Wolfram Research (2010), Undefined, Wolfram Language function, https://reference.wolfram.com/language/ref/Undefined.html.
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Wolfram Research (2010), Undefined, Wolfram Language function, https://reference.wolfram.com/language/ref/Undefined.html.Text
Wolfram Research (2010), Undefined, Wolfram Language function, https://reference.wolfram.com/language/ref/Undefined.html.
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Wolfram Research (2010), Undefined, Wolfram Language function, https://reference.wolfram.com/language/ref/Undefined.html.CMS
Wolfram Language. 2010. "Undefined." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/Undefined.html.
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Wolfram Language. 2010. "Undefined." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/Undefined.html.APA
Wolfram Language. (2010). Undefined. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Undefined.html
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Wolfram Language. (2010). Undefined. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Undefined.htmlBibTeX
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@misc{reference.wolfram_2025_undefined, author="Wolfram Research", title="{Undefined}", year="2010", howpublished="\url{https://reference.wolfram.com/language/ref/Undefined.html}", note=[Accessed: 13-May-2025
]}BibLaTeX
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@online{reference.wolfram_2025_undefined, organization={Wolfram Research}, title={Undefined}, year={2010}, url={https://reference.wolfram.com/language/ref/Undefined.html}, note=[Accessed: 13-May-2025
]}