@ARTICLE{Hanus24LOPSTR,
author       = {Hanus, M.},
title        = {Improving Logic Programs by Adding Functions},
year         = {2024},
booktitle    = {Proceedings of the 34th International Symposium on Logic-Based
                Program Synthesis and Transformation (LOPSTR 2024)},
pages        = {27-44},
publisher    = {Springer LNCS 14919},
abstract = {
Logic programming is based on defining relations.
Functions are often considered as syntactic sugar
which can be transformed into predicates so that
their logic is not used for computational purposes.
In this paper, we present a method to use functions
to improve the operational behavior of logic programs
without loosing the flexibility of logic programming.
For this purpose, predicates and goals are transformed
into functions and nested expressions.
By evaluating these functions in a demand-driven manner
wherever possible and taking potential failures into account,
we ensure that the execution of the transformed programs
will never require more steps than the original programs
but can decrease the number of steps---in the best case
reducing infinite search spaces to finite ones.
Thus, we obtain a systematic method to improve the operational
behavior of logic programs without changing their semantics.
}
}