Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On infinite words avoiding a finite set of squares   Building an infinite square-free word by appending one letter at a time while
simultaneously avoiding the creation of squares is most likely to fail. When
the alphabet has two letters this approach is impossible. When the alphabet has
three or more letters, one will most probably create a word in which the
addition of any letter invariably creates a square. When one restricts the set
of undesired squares to a finite one, this can be possible. We study the
constraints on the alphabet and the set of squares which permit this approach
to work.

15
The categories of this paper are: nucl-ex
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
13
The categories of this paper are: quant-ph
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
4
The categories of this paper are: cond-mat
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga