Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: A cancellation-free antipode formula (for uniform matroids) for the
  restriction-contraction matroid Hopf algebra
25
The categories of this paper are: patt-sol
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
3
The categories of this paper are: physics