not an element of
Say it “is not in”
The thing on the left is not in the set.
Example
In code
x not in SWhere you’ll see it in ML
Excluding cases, e.g. a token not in the vocabulary.
Say it “is not in”
The thing on the left is not in the set.
x not in SExcluding cases, e.g. a token not in the vocabulary.