Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: A rational map between two threefolds   A rational map between certain specific threefolds is given in an explicit
manner.

6
The categories of this paper are: astro-ph
27
The categories of this paper are: comp-gas
19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg
17
The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat
18
The categories of this paper are: econ
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th