Definition squash_unsquash := K.squash_unsquash.Definition unsquash_squash := K.unsquash_squash.Definition knot_age1 := K.knot_age1.Definition knot_level := K.knot_level.Module K := K'.

Lemma approx_approx2 : forall m n, approx n = approx (m+n) oo approx n.