Program Definition approx (n:nat) (p: (pred rmap)) : (pred rmap) :=
    fun w => level w < n /\ p w.

(* Specifications: *)
Lemma unsquash_squash : forall n rm, (unsquash (squash (n,rm))) = (n,rmap_fmap (approx n) rm).
Lemma approx_K_approx: approx = K.approx.
Lemma unsquash_squash : forall n rm, (unsquash (squash (n,rm))) = (n,rmap_fmap (approx n) (approx n) rm).