Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Modularization, Composition, and Hierarchization of Petri Nets with
  Heraklit   It is known for decades that computer-based systems cannot be understood
without a concept of modularization and decomposition. We suggest a universal,
expressive, intuitively attractive composition operator for Petri nets,
combined with a refinement concept and an algebraic representation of nets and
their composition. Case studies show exemplarily, how large systems can be
composed from tiny net snippets. In the future, more field studies are needed
to better understand the consequences of the proposed ideas in the real world.

3
The categories of this paper are: physics
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
6
The categories of this paper are: astro-ph
25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
5
The categories of this paper are: gr-qc
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph