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Identity function
In mathematics, a function that always returns the same value that was used as its argument / From Wikipedia, the free encyclopedia
Not to be confused with Null function or Empty function.
In mathematics, an identity function, also called an identity relation, identity map or identity transformation, is a function that always returns the value that was used as its argument, unchanged. That is, when f is the identity function, the equality f(x) = x is true for all values of x to which f can be applied.
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