What is Undefined
?¶
In the last section we looked up the documentation for Undefined
. What exactly is it?
To find it in the WMA docs we add the name after https://reference.wolfram.com/language/ref/
which gives https://reference.wolfram.com/language/ref/Undefined
It is listed as a “Built-in Symbol”. In contrast to the other examples and indeed most of the kinds of things you are likely to add, this one is not a function, but a “symbol”. The description for this is “a symbol that represents a quantity with no defined value”.
Asking in the Q/A section of mathics-core we learn that
Attributes[Undefined]={Protected}
.
Another place where you may be able to get information about Mathematica is StackExchange Mathematica and Wolfram Language
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