Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Type System for First-Class Layers with Inheritance, Subtyping, and
  Swapping   Context-Oriented Programming (COP) is a programming paradigm to encourage
modularization of context-dependent software. Key features of COP are
layers---modules to describe context-dependent behavioral variations of a
software system---and their dynamic activation, which can modify the behavior
of multiple objects that have already been instantiated. Typechecking programs
written in a COP language is difficult because the activation of a layer can
even change objects' interfaces. Inoue et al. have informally discussed how to
make JCop, an extension of Java for COP by Appeltauer et al., type-safe.
  In this article, we formalize a small COP language called ContextFJ$_{<:}$
with its operational semantics and type system and show its type soundness. The
language models main features of the type-safe version of JCop, including
dynamically activated first-class layers, inheritance of layer definitions,
layer subtyping, and layer swapping.

24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
6
The categories of this paper are: astro-ph
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
37
The categories of this paper are: supr-con
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
32
The categories of this paper are: atom-ph
8
The categories of this paper are: hep-ex