Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On Green's Functions and Positive, Self-Adjoint, Elliptic Differential
  Operators   This paper is being replaced by another of the author's that contains a brief
summary of the problem of positivity of Green's functions, heat kernels, and
principal eigenvalues of higher-order elliptic differential operators.

37
The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph