Unsolvable Exponential: Solving x = y^y

[soandos]

this has been realized, and that is why the thread talks about Newtons method, and other methods of approximation. there are also problems with these methods (in general) when the function is not continuous. (i.e. for negative x)

also, somebody correct me if i am wrong but the expression (-1)^(2/7) for example can have more than one value, right?