Preferred well-founded semantics for logic programming by alternating
  fixpoints: Preliminary report
  We analyze the problem of defining well-founded semantics for ordered logic
programs within a general framework based on alternating fixpoint theory. We
start by showing that generalizations of existing answer set approaches to
preference are too weak in the setting of well-founded semantics. We then
specify some informal yet intuitive criteria and propose a semantical framework
for preference handling that is more suitable for defining well-founded
semantics for ordered logic programs. The suitability of the new approach is
convinced by the fact that many attractive properties are satisfied by our
semantics. In particular, our semantics is still correct with respect to
various existing answer sets semantics while it successfully overcomes the
weakness of their generalization to well-founded semantics. Finally, we
indicate how an existing preferred well-founded semantics can be captured
within our semantical framework.
