Like the author said, this is an old idea that's recently been revived. (I agree that the article was quite well done.) Most of the ideas he described, like g

Like the author said, this is an old idea that's recently been revived. (I agree that the article was quite well done.) Most of the ideas he described, like goals and unification, have been a feature of logic programming for ages. Prolog is the classic language in logic programming --- it attracted major interest during the AI bubble in the 1980s and survives mainly as an educational language today. It's worth a look, particularly since there are so many educational materials available.