Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Maximal r-Diameter Sets and Solids of Constant Width   We recall the definition of an r-maximal set in a metric space as a maximal
subset of diameter r. In the special case when the metric space is Euclidean
such a set is exactly a solid of constant diameter r. In the process of
reviewing the theory of these objects we provide a simple construction which
generates a large class of such solids.

23
The categories of this paper are: solv-int
3
The categories of this paper are: physics
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th
12
The categories of this paper are: nucl-th