  We present a method for extracting general modules for ontologies formulated
in the description logic ALC. A module for an ontology is an ideally
substantially smaller ontology that preserves all entailments for a
user-specified set of terms. As such, it has applications such as ontology
reuse and ontology analysis. Different from classical modules, general modules
may use axioms not explicitly present in the input ontology, which allows for
additional conciseness. So far, general modules have only been investigated for
lightweight description logics. We present the first work that considers the
more expressive description logic ALC. In particular, our contribution is a new
method based on uniform interpolation supported by some new theoretical
results. Our evaluation indicates that our general modules are often smaller
than classical modules and uniform interpolants computed by the
state-of-the-art, and compared with uniform interpolants, can be computed in a
significantly shorter time. Moreover, our method can be used for, and in fact
improves, the computation of uniform interpolants and classical modules.
