Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Homomorphisms and principal congruences of bounded lattices   Two years ago, I characterized the order $\Princl L$ of principal congruences
of a bounded lattice $L$ as a bounded order.
  If $K$ and $L$ are bounded lattices and $\gf$ is a \zo homomorphism of $K$
into~$L$, then there is a natural isotone \zo-map $\gf_{\Hom}$ from $\Princl K$
into $\Princl L$.
  We prove the converse: For bounded orders $P$ and $Q$ and an isotone \zo map
$\gy$ of $P$ into $Q$, we represent $P$ and $Q$ as $\Princl K$ and $\Princl L$
for bounded lattices $K$ and $L$ with a \zo homomorphism $\gf$ of $K$ into $L$,
so that $\gy$ is represented as $\gf_{\Hom}$.

21
The categories of this paper are: adap-org
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
26
The categories of this paper are: bayes-an
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an