Patenting inventions based on algorithms

Arithmetic algorithms alone are not patentable, but physical things are. The patentability of concepts embodying both algorithmic and physical elements has been questioned for a long time. In the past, patentability was decided by criteria (such as statutory class and novelty) detailed in the patent statute. In the recent Flook case, the US Supreme Court says that arithmetic algorithms are nonpatentable because they are not `inventions´ in the first place, whether or not they are new. The effect of this decision on the patentability of methods and systems embodying both arithmetic and physical elements is known. Rough guidelines for patentability are provided.