Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: (1 + d/dz)^(-1)   We investigate the structure of fully non-linear P.D.E.'s in holomorphic
functions, with emphasis on the functorial generalisation of so called
"irregular" O.D.E.'s. Highlights are an implicit function theorem removing the
perturbation conditions of Nash-Moser type, best possible existence results
when the singularity of the linearised P.D.E. is at worst bi-dimensional, and
various, again optimal, corollaries on existence of centre manifolds and
conjugation to normal form of 3-dimensional vector fields.

23
The categories of this paper are: solv-int
28
The categories of this paper are: alg-geom
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys