Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Overview of "Structure behind Mechanics"   This letter proposes a new scenario to solve the structural or conceptual
problems remained in quantum mechanics, and gives an overview of the theory
proposed in quant-ph/9906130 (including quant-ph/9909025 and quant-ph/0001015).

30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc
9
The categories of this paper are: nlin
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
4
The categories of this paper are: cond-mat
21
The categories of this paper are: adap-org
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas