Patent 5,893,120 reduced to mathematical formulae
For a different perspective, "What colour are your bits?" ( http://ansuz.sooke.bc.ca/entry/23 ) is an excellent read.It could be argued that programs and ideas built up through the machinery of mathematics are unpatentable, whereas programs and ideas built through the machinery of engineering are.The law may ignore the actual content in favor of looking at the mechanism of discovery and/or usage.