Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A "classification" of congruence primal arithmetical algebras   We classify essential algebras whose irredundant non-refinable covers consist
of primal algebras. The proof is obtained by constructing one to one
correspondence between such algebras and partial orders on finite sets.
Further, we prove that for a finite algebra, it has an irredundant
non-refinable cover consists of primal algebras if and only if it is the both
congruence primal and arithmetical. Finally, we obtain combinatorial
description of congruence primal arithmetical algebras.

3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
16
The categories of this paper are: stat
0
The categories of this paper are: hep-ph
17
The categories of this paper are: q-fin
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
6
The categories of this paper are: astro-ph
22
The categories of this paper are: chao-dyn