Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the construction of evolution equations admitting a master symmetry   A method for constructing evolution equations admitting a master symmetry is
proposed. Several examples illustrating the method are presented. It is also
noted that for certain evolution equations master symmetries can be useful for
obtaining new conservation laws from a given one.

27
The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org
6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
12
The categories of this paper are: nucl-th
3
The categories of this paper are: physics
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol