CR-Prolog with Ordered Disjunction

We present CR-Prolog , an extension of CR-Prolog with an improved semantics, and allowing ordered disjunction in the head of both regular rules and consistency-restoring rules. The new semantics yields intuitive conclusions in cases when CR-Prolog would give unintuitive results. The use of ordered disjunction often allows for a more concise, easier to read, representation of knowledge. We also show how CR-Prolog can be used to represent preferences intended both as strict preferences (like in CR-Prolog), and as desires (like in LPOD, where ordered disjunction was initially introduced). Finally, we show how the new language can be used to represent complex knowledge and to perform fairly sophisticated reasoning tasks.