dwfs is a system for computing the D-WFS semantics of
disjunctive logic programs. This system has been
developed as a part of the research project
The D-WFS semantics has first been introduced by Brass and Dix. For a description, see
dwfs program computes, from an input program in clausal
form, the residual program or program remainder, from which the D-WFS
semantics can be read off directly. Program remainders, which can only
be computed for non--disjunctive programs, are
S. Brass, B. Freitag, U. Zukowski:
Transformation Based Bottom-Up
Computation of the Well-Founded Model.
In: J. Dix, L. Pereira, T. Przymusinski (eds.):
Nonmonotonic Extensions of Logic Programming
Pages 171-201, LNAI 1216, Springer, Berlin.
They are equivalent to residual programs, but are polynomial in size relatively to the size of the original input program, whereas residual programs can grow to be exponential in size.
There are three different
dwfs can perform:
dwfscan compute the residual program using a least-fixpoint approach.
dwfscan compute the residual program by application of all program transformations in turn.
dwfscan compute the program remainder.
dwfswas written in Eclipse Prolog by Katrin Erk.
The prototype implementation and some test cases are available as a gzipped tar file. For a description of parameters, flags and input format, see the user's guide .
If you have questions or comments, please send an email to
Jürgen Dix or