Yes. And as we know, Prolog is turing complete. Therefore†, anything which the salesman could do if he could hear ever bar patron's conversation, he can do by

Yes. And as we know, Prolog is turing complete. Therefore†, anything which the salesman could do if he could hear ever bar patron's conversation, he can do by a clever set of ad deployments (though it may be orders of magnitude less efficient). ---- † Yes, I'm stretching the "proof" beyond its breaking point here.