a few more simplifications
Some #ifdef tweaks
uncurry/pair
remove special pair translation for now
(@.) --> (:.) in decompL & decompR. Helps CRC example
Replaced ConstP in Prim with ConstC in :->
-- TODO: Do we really need both Prim and ConstC?
|||/Inl/Inr rules
a bit of reordering
don't import Prim