Very nice NYTimes article about problems arising for existing practice in the US patent office
Byte article detailing patent law
U.S. patent #4,935,877 (to John Koza).
(doesn't look expired as of Wed Oct 27 11:46:09 PDT 1999)
Bucket Brigade covered by
U.S. patent #4,697,242
: J.H. Holland and A. Burks, "Adaptive computing system capable of learning and discovery", 1985, issued Sept 29 1987.
W3C statement on the microsoft "Style Sheet" patent