t> We elaborate on earlier work proposing general criteria to control unfolding during partial deduction of logic programs. We study several techniques relying on more general and more powerful well-founded orderings. In particular, we extend our framework to incorporate lexicographical priorities between argument positions in a goal. We show that this handles some remaining deficiencies in previous methods. We emphasize the development of fully automatic algorithms for finite unfolding,

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... g the use of ad hoc techniques. Through an extensive formalization, we convey an understanding of the common principles underlying the various algorithms. Finally, we exhibit how our structure-based unfolding framework can be adapted to cope with datalog-like constant manipulating predicates in a satisfactory way.