Nienhuys-Cheng, S-H.; Laer, W. van; Ramon, J.; Raedt, L. de - Erasmus Research Institute of Management (ERIM), ERIM … - 2000
Inductive Logic Programming considers almost exclusively universally quantied theories. To add expressiveness, prenex conjunctive normal forms (PCNF) with existential variables should also be considered. ILP mostly uses learning with refinement operators. To extend refinement operators to PCNF,...