Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the relationship of Mathematics to the real world   In this article, I discuss the relationship of mathematics to the physical
world, and to other spheres of human knowledge. In particular, I argue that
Mathematics is created by human beings, and the number $\pi$ can not be said to
have existed $100,000$ years ago, using the conventional meaning of the word
`exist'.

31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
4
The categories of this paper are: cond-mat
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
8
The categories of this paper are: hep-ex