Aproximating the Well-Founded Semantics for Normal Logic Programs using Abstract Interpretation. - Roberta Gori; E. Lastres; R. Moreno; Fausto Spoto (APPIA-GULP-PRODE, 1998)

A Semantics for Logic Programs based on First Order Hereditary Harrop Formulas. - E. Lastres; R. Moreno (APPIA-GULP-PRODE, 1998)