Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: General and alien solutions of a functional equation and of a functional
  inequality   The purpose of the present paper is to solve (under some assumption on the
domain) the equation $$ g(x+y)-g(x)-g(y)=xf(y)+yf(x). $$ After determining the
general solutions, we will investigate the so--called alien solutions. %More
precisely, we will examine the cases when the above equation implies that
%$g(x+y)=g(x)+g(y)$ and $xf(y)+yf(x)=0$. %Concerning this, necessary and
sufficient conditions will be provided. Finally, we will discuss the real
solutions of the following related functional inequality: $$
g(x+y)-g(x)-g(y)\geq xf(y)+yf(x). $$

19
The categories of this paper are: eess
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg