Category:Prolog examples needing attention

These Prolog examples need attention. They may be incorrect, poorly-written or in some other way unsatisfactory in their current state on their current page. If you know Prolog, take a look at them and see if there's something you can do. The people best suited for ensuring the quality of Prolog examples on Rosetta Code are the people who know the language. If that's you, we'd appreciate it if you would lend a hand.