Rule-Based Expression in Copyright Law

Should copyright be extended to a work of authorship that consists of rules for producing another work of authorship, or, conversely, to a work that owes its genesis to the application of such rules? If 'yes' for either, are 'A' and 'B' two separate works, or two dimensions of the same work? In the leading case, Southco, Inc. v. Kanebridge Corp., the plaintiff claimed copyright protection for the individual serial numbers generated by a set of proprietary numbering rules; similar issues, however, are raised by any work whose claim to originality comes from how its literal elements are structured, such as compilations, games, recipes, blueprints, score sheets, taxonomies, price estimates, and computer programs. The more basic problem is the relationship between function and expression in works of authorship generally, and what freely willed self-expression in those works requires. I trace the doctrinal forebears of Southco to the seminal case of Baker v. Selden, and focus on the question of how to evaluate the copyright status of a work of authorship whose rule-basis engenders its textual form in an invariant and predetermined manner.