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

Lemma approx_spec': forall n p ko, (approx n p) ko = if (le_gt_dec n (level (fst ko))) then False else proj1_sig p ko.