$$\left(1+\frac{d}{dz}\right)^{-1}$$

only a preprint, though: http://arxiv.org/abs/1203.3045

$$\left(1+\frac{d}{dz}\right)^{-1}$$

only a preprint, though: http://arxiv.org/abs/1203.3045

EDIT: As of 3 Oct 2016 "This paper has been withdrawn due to an error in the proof of Claim I.3.5"