Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Universal ringed spaces   We construct affine spaces, projective spaces and grassmannians in the
ca\-te\-gory of ringed spaces. We show how finite posets and sheaves of rings
on them appear in a natural way.

17
The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
8
The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
7
The categories of this paper are: hep-th
24
The categories of this paper are: dg-ga