Kast in k

I created this diff for use in managing the discussion on the KORE syntax. We may choose to close it rather than merge it, I just need a place to put comments.
I like this idea. We don't need the absolute minimal representation. We also want the definition to be somewhat readable. At one point we have to debug it. I would like to be able to make sense of what's inside, especially if we're talking about quadratic behaviors.