Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Lie group classification of first-order delay ordinary differential
  equations   A group classification of first-order delay ordinary differential equation
(DODE) accompanied by an equation for delay parameter (delay relation) is
presented. A subset of such systems (delay ordinary differential systems or
DODSs) which consists of linear DODEs and solution independent delay relations
have infinite-dimensional symmetry algebras, as do nonlinear ones that are
linearizable by an invertible transformation of variables. Genuinely nonlinear
DODSs have symmetry algebras of dimension $n$, $0 \leq n \leq 3$. It is shown
how exact analytical solutions of invariant DODSs can be obtained using
symmetry reduction.

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The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
31
The categories of this paper are: ao-sci
6
The categories of this paper are: astro-ph
3
The categories of this paper are: physics
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
20
The categories of this paper are: acc-phys