Lambda the Ultimate

While investigating the relationship between modules, their versions and mutual dependencies I came across one hard problem: Given a repository of modules (like the one provided by maven), select such configuration of the module versions so all their dependencies are satisfied.

After a little bit of thinking I concluded that this is NP-complete problem. I have even written down a proof.
I guess many LtU members are qualified to review the proof for soundness. Would you be so kind and tell me if there is anything wrong with it? Thanks.

Visit the proof.