So you mean Prolog? It's not quite IBM's. And yes, many expert systems are about guessing what the user wants rather than providing an accurate answer - and ref

So you mean Prolog? It's not quite IBM's. And yes, many expert systems are about guessing what the user wants rather than providing an accurate answer - and refinement later. They're called search engines, I heard Google was making a darn good one in 1998.