abstract = "This work introduces automatically defined functions
(ADFs) for learning classifier systems (LCS). ADFs had
been successfully implemented in genetic programming
(GP)for various domain problems such as multiplexer and
even-odd parity, but they have never been attempted in
LCS research field before. ADFs in GP contract program
trees and shorten training times whilst providing
resilience to destructive genetic operators. We have
implemented ADFs in Wilson's accuracy based LCS, known
as XCS [14]. This initial investigation of ADFs in LCS
shows that the multiple genotypes to a phenotype issue
in feature rich encodings disables the subsumption
deletion function. The additional methods and increased
search space also leads to much longer training times.
This is compensated by the ADFs containing useful
knowledge, such as the importance of the address bits
in the multiplexer problem. The ADFs also create masks
that autonomously subdivide the search space into areas
of interest and uniquely, areas of not interest. The
next stage of this work is to implement simplification
methods and then determine methods by which ADFs can
facilitate scaling for more complex problems within the
same problem domain.",
notes = "Also known as \cite{2002022} Distributed on CD-ROM at
GECCO-2011.