-lemma cnx_inv_sort: ∀h,o,G,L,s. ⦃G, L⦄ ⊢ ⬈[h, o] 𝐍⦃⋆s⦄ → deg h o s 0.
-#h #o #G #L #s #H
-lapply (H (⋆(next h s)) ?) -H /2 width=2 by cpx_ess/ -G -L #H
-elim (tdeq_inv_sort1 … H) -H #s0 #d #H1 #H2 #H destruct
-lapply (deg_next … H1) #H0
-lapply (deg_mono … H0 … H2) -H0 -H2 #H
-<(pred_inv_refl … H) -H //
-qed-.
-
-lemma cnx_inv_abst: ∀h,o,p,G,L,V,T. ⦃G, L⦄ ⊢ ⬈[h, o] 𝐍⦃ⓛ{p}V.T⦄ →
- ⦃G, L⦄ ⊢ ⬈[h, o] 𝐍⦃V⦄ ∧ ⦃G, L.ⓛV⦄ ⊢ ⬈[h, o] 𝐍⦃T⦄.
-#h #o #p #G #L #V1 #T1 #HVT1 @conj
-[ #V2 #HV2 lapply (HVT1 (ⓛ{p}V2.T1) ?) -HVT1 /2 width=2 by cpx_pair_sn/ -HV2
-| #T2 #HT2 lapply (HVT1 (ⓛ{p}V1.T2) ?) -HVT1 /2 width=2 by cpx_bind/ -HT2
+lemma cnx_inv_abst: ∀h,p,G,L,V,T. ❪G,L❫ ⊢ ⬈𝐍[h] ⓛ[p]V.T →
+ ∧∧ ❪G,L❫ ⊢ ⬈𝐍[h] V & ❪G,L.ⓛV❫ ⊢ ⬈𝐍[h] T.
+#h #p #G #L #V1 #T1 #HVT1 @conj
+[ #V2 #HV2 lapply (HVT1 (ⓛ[p]V2.T1) ?) -HVT1 /2 width=2 by cpx_pair_sn/ -HV2
+| #T2 #HT2 lapply (HVT1 (ⓛ[p]V1.T2) ?) -HVT1 /2 width=2 by cpx_bind/ -HT2