Are software logic, structure and sequence protectable by copyright?

The author indicates that at the present time, it is uncertain whether software logic, structure, and sequence are protectable under US copyright law. Courts began dealing with these issues approximately 11 years ago. The applicable provisions of the present US Copyright Act have been in effect approximately the same period of time. The near future does not hold promise that US courts will conclusively establish the levels of abstraction, if any, of a computer program which are entitled to copyright protection.<>