The algorithm definiteness inquiry for corresponding means-plus-function structure is not one of literal support but whether “a person of ordinary skill in the art would understand the algorithmic structure for performing the claimed function.” Even distinct but related aspects may be looked to for gleaning an algorithm with which to implement a given function. Moreover, not all computer-implemented means-plus-function elements require algorithmic structure: “Aristocrat and related cases hold that, for means-plus-function claims, the corresponding structure in the specification must be a step-by-step algorithm, unless a general purpose computer is sufficient for performing the claimed function.”
Background / Facts: The patent being asserted here is directed an “automated exchange” for trading financial instruments, which is distinguished from the traditional, floor-based “open-outcry” system. The claims recite “means for matching” a certain portion of an incoming order or quotation for such instruments with professional orders or quotations stored in memory “on a pro rata basis.”
Issue(s): Whether the specification discloses an algorithm for identifying a counterpart order on a pro rata basis.
Holding(s): Yes. Citing certain numerical examples in the disclosure, the court noted that “the specification explains that orders are matched in proportion to the size of the order requested by the professional. It also explains that, if the order sizes are equal for two professionals, the professional who placed the first order, gets matched first. Based upon this discussion of size-based, pro rata matching, a person of ordinary skill in the art would understand the algorithmic structure for performing the claimed function.” Further, although the court construed pro rata “matching” and pro rata “allocating” as distinct processes, the discussion of pro rata allocating may provide structure for pro rata matching. “The disclosure of pro rata allocation does not detract from the disclosure of pro rata matching. Indeed, a person of ordinary skill in the art would likely look to the similar pro rata allocating process when implementing pro rata matching.”