Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On graceful labelings of trees   We prove via a composition lemma, the Kotzig-Ringel-Rosa conjecture, better
known as the Graceful Labeling Conjecture. We also prove via a stronger version
of the composition lemma a stronger form of the Graceful Labeling Conjecture.

25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
15
The categories of this paper are: nucl-ex
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
1
The categories of this paper are: cs
4
The categories of this paper are: cond-mat
16
The categories of this paper are: stat