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_spec': forall n p k, ((fun (p: knot -> Prop) ko => p (@fst _ unit ko)) oo app_pred) (approx n p) k = if (le_gt_dec n (level (fst k))) then False else ((fun (p: knot -> Prop) ko => p (@fst _ unit ko)) oo app_pred) p k.