Talk:Inverse function rule
Hawthorne - I removed the note because ex is defined for all complex numbers, and so is ln(x). (See, for example, Euler's formula.)
Also, I think that there are a lot of people unfamiliar with the universal operator, and it makes the formula overly confusing. I really don't think one needs to be that precise for something that goes without saying, especially when it obscures the simplicity of the concept.
Perhaps the set operators can be separated from the main formula? Perhaps that part (along with the right and left inverse) can have it's own small section on the page? I think this would improve the page.
-User:Kevin_baas 2003.06.24