Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Reduction of systems of first-order differential equations via
  Lambda-symmetries   The notion of lambda-symmetries, originally introduced by C. Muriel and J.L.
Romero, is extended to the case of systems of first-order ODE's (and of
dynamical systems in particular). It is shown that the existence of a symmetry
of this type produces a reduction of the differential equations, restricting
the presence of the variables involved in the problem. The results are compared
with the case of standard (i.e. exact) Lie-point symmetries and are also
illustrated by some examples.

31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
3
The categories of this paper are: physics
4
The categories of this paper are: cond-mat
16
The categories of this paper are: stat
23
The categories of this paper are: solv-int
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
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The categories of this paper are: eess
36
The categories of this paper are: cmp-lg