::: That article is about the inverse of a general function, in a set theory framework. You inserted a formula which is valid for only very special functions, on the real line, and did not bother to explain when that formula is valid.  

 ::: Both before and after your formula the discussion is about fully general functions.  Your text stands in the middle, very confusing and unclear. I see it got deleted.  

 ::: If you want to put it back, please put it at the end of the article, explain for what kind of  functions it is valid (what their domain is, their range, what type of functions). 

 ::: But really, I think your text is not valuable in that article. I may delete it anyway.