[ffpenile] Enacting policy with context

When enacting policy, e.g., law, let the policy also state assumptions for how the world works, a model for the world, and how the policy is expected to work within the model.

Legislators might disagree on how the world works, but might agree that the policy is a good idea.  In which case, the policy can have multiple models attached to it.

If it later becomes clear that the model described in the policy is not how the world actually works, then the law can be revisited and perhaps struck down.