Talk:Many-one reduction

wrong use of inverse function
The first part of the definition for formal languages ends with the statement that $$A= f^{-1}(B)$$. I think this is wrong, because $$f$$ does not need to be a surjective function and therefore $$f^{-1}$$ does not need to exist.

--JonathenHarker (talk) 13:26, 21 October 2019 (UTC)