Nerd.
In 2005 I used Prolog to a solved pathfinding for competive maps in CS 1.6 based off weighted examples form interviewing a 'professionals' calls, even had a plugin architecture to extend each map, though it only worked well for Dust2 before I had to present. Way more practical. Cough.
That was fun. Now I want to find the code...
Here is my crowning achievement from back then in 1993 - a genetic programming simulator that evolved ants to follow pheromone trails in pure prolog.
http://www.cs.cmu.edu/Groups/AI/areas/genetic/gp/systems/gp_...
Enjoy.