Item

Abstract

Standard logic programming languages like Prolog lack the possibility of
dealing with modalities and/or sorts. A first idea how to overcome this problem
(and that without changing anything on Prolog itself) would be to apply the
well-known relational translation approaches from modal and sorted logic into
first-order predicate logic and to feed this translation result into Prolog.
This, however, leads into other problems: firstly, the transformed problem is
usually of much bigger size (number of clauses) than the original one and,
secondly, very often it is not even in Horn form anymore. In this paper a
translation approach is proposed which avoids both of these problems, i.e.\ the
number of clauses after translation is exactly as big as it would have been if
we simply ignored the modal operators and sort restrictions and, also, the
result is in Horn form provided it was already before (modulo modal operators
and sorts).