Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On time-dependent symmetries and formal symmetries of evolution
  equations   We present the explicit formulae, describing the structure of symmetries and
formal symmetries of any scalar (1+1)-dimensional evolution equation. Using
these results, the formulae for the leading terms of commutators of two
symmetries and two formal symmetries are found. The generalization of these
results to the case of system of evolution equations is also discussed.

1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess
27
The categories of this paper are: comp-gas
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci