Even when a patent claim tries to tie a mathematical algorithm to a machine, the legal tests get all convoluted. For example, in Ex Parte Gutta (BPAI 2009) (de

Even when a patent claim tries to tie a mathematical algorithm to a machine, the legal tests get all convoluted. For example, in Ex Parte Gutta (BPAI 2009) (decided August, made precedential December, 2009), the current USPTO test for patentability in such a case is set out: "(1) Is the claim limited to a tangible practical application, in which the mathematical algorithm is applied, that results in a real-world use (e.g., 'not a mere field-of-use label having no significance')? (2) Is the claim limited so as to not encompass substantially all practical applications of the mathematical algorithm either 'in all fields' of use of the algorithm or even in 'only one field?'" If the answer to either question is "no," the claim fails. In that case, the claim indicated that a processor (working with memory) is configured to identify a "mean item" whose symbolic value minimizes the variance of a set. (See http://www.patentlyo.com/patent/2009/12/patentable-subject-matter-of-a-machine-that-uses-a-mathematical-algorithm.html http://www.patentlyo.com/patent/2009/12/patentable-subject-m... for a visual depiction) The BPAI found that the claim failed the first prong by not limiting itself to any "tangible practical application in which the mathematical algorithm is applied that result in a real-world use." Likewise, the claim failed the second prong because it "encompasses substantially all practical applications" of the algorithm. "That is we are unable to identify any other practical application [of the algorithm] outside of the broadly defined claim." Any time someone tries to grab a monopoly on an algorithm, there is a real danger to innovation. Sometimes (as here) common sense prevails but often it does not.