For those interested in a plans and patterns approach to chess, I've found a reference to a PDF of two appendices of technical notes for Wilkins' Paradise program:
http://www.ai.sri.com/pubs/files/465.pdf
(It appears that the last third of the document is an accidental repeat of the second third.)
The first appendix is a list of productions, each of which is a blob of Lisp that recognizes some chess pattern. The second appendix is text that describes the purpose of the productions.
More on plans and patterns in Paradise
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