This video is a walkthrough of Clojure core.logic.
There is also a bootleg video of a talk from Strange Loop 2012.
The presentation starts with a short review of how to use core.logic before Nolen goes into the implementation details. core.logic is based on miniKanren, described in The Reasoned Schemer.
David Nolen draws on some of the giants of Computer Science in recent years. Alan Kay, Gregor Kiczales, Peter Norvig, and more. I love to see the products of great minds folded into Clojure and ready at my fingertips.