> Why not just do relational programming - prolog or sql. The lisp weenies still don't get it.

John McCarthy was the first to recommend using logic in programs with his advice taker proposal. This inspired the logic programming paradigm:

http://www-formal.stanford.edu/jmc/mcc59/mcc59.html

Paul Graham (creator of the hacker news site) has an entire chapter in his book On Lisp on embedding prolog:

http://www.bookshelf.jp/texi/onlisp/onlisp_25.html

Peter Norvig's Paradigms of Artificial Intelligence programming includes an implementation of prolog in Lisp:

http://norvig.com/paip/prolog.lisp

Common Lisp relations: an extension of Lisp for logic programming proposed a mechanism for logic programming back in 1988:

http://www.lw20.com/2011051092557312.html

Franz. Inc is developing Allegro Prolog as an extension to Common Lisp:

http://www.franz.com/support/documentation/8.2/doc/prolog.ht...

The Clojure programming language includes relational programming functionality through the core/logic module:

https://github.com/frenchy64/Logic-Starter/wiki

Racklog is an embedding of Prolog-style programming in Racket.

http://docs.racket-lang.org/racklog/

The Shen programming languages includes a fully functional embedded prolog system:

http://shenlanguage.org/learn-shen/prolog.html

CycL is a declarative ontology language based upon classical first-order language which includes support for ontology components including parts and relations:

http://www.cyc.com/cycdoc/ref/cycl-syntax.html

What is it that we don't get again?