Thanks for your finding these discussion.
As Jochen said: Ruby and Python calculate `-2**4` and return `-16`,
Groovy returns the same value currently.
But Scala/Excel returns `16`...
Maybe Ruby/Python/Groovy behaves properly for most people...
> I just checked Ruby and Python and there -2**4 will return -16, same for
> -2^4 in
> Lua. So now I am wondering if that is the right thing for unary minus
> bye blackdrag