a) In view of §1 par. 3. Nr. 1 PatG, mathematical methods are patentable only when they contribute to the solution of a specific technical problem with technical means.
b) A mathematical method can be considered non-technical only when it does not have, in the context of the claimed teaching, any relation to the purposeful use of natural forces.
c) A sufficient relation to the purposeful use of natural forces exists when the mathematical method is used for the purpose of obtaining more reliable information on the state of an airplane using the available measurement data to thereby influence the functioning of the system used for detecting that state.
d) Subject-matter which is novel and based on an inventive step cannot be considered non-patentable only because it does not offer any recognizable advantage over the prior art.The decision clarifies that the exception of §1 par. 3. Nr. 1 PatG has to be interpreted very narrow and that even a remote relation to a tangible technical device ("the purposeful use of natural forces") is sufficient.
Letter d) highlights an interesting contrast between the German case-law and the case-law of the technical boards of appeal, where a technical advantage is sometimes required.