The many ways confusion

[rjack]

> > If there is a single way (or maybe a very, very limited way) of 
> > expressing an idea, it is said that the idea and the expression 
> > have "merged" and therefore the expression is not protectable by 
> > copyright.
> >
> > That has nothing to do with whether there is a patent that covers a
> > method that can be implemented in software.  There is, in general, 
> > a variety of ways to implement ("express") the method, and
> > therefore each implementation can have its own copyright.

See Lexmark International, Inc. v. Static Control Components, Inc., 387 
F.3d 522 (6th Cir. 2004):


"Nor does Nimmer support the district court’s “a number of different
ways” reasoning. As a matter of practice, Nimmer is correct that courts 
most commonly discuss the idea-expression dichotomy in
considering whether an original work and a partial copy of that work 
are“substantially similar” (as part of prong two of the infringement 
test), since the copyrightability of a work as a whole (prong one) is 
less frequently contested. But the idea-expression divide figures into 
the substantial similarity test not as a measure of “similarity”; it 
distinguishes the original work’s protectable elements from its 
unprotectable ones, a distinction that allows courts to determine 
whether any of the former have been copied in substantial
enough part to constitute infringement."