-lemma csx_inv_lref: ∀h,G,L,i. ⦃G, L⦄ ⊢ ⬈*[h] 𝐒⦃#i⦄ →
- ∨∨ ⬇*[Ⓕ, 𝐔❴i❵] L ≘ ⋆
- | ∃∃I,K. ⬇*[i] L ≘ K.ⓤ{I}
- | ∃∃I,K,V. ⬇*[i] L ≘ K.ⓑ{I}V & ⦃G, K⦄ ⊢ ⬈*[h] 𝐒⦃V⦄.
-#h #G #L #i #H elim (drops_F_uni L i) /2 width=1 by or3_intro0/
-* * /4 width=9 by csx_inv_lref_pair, ex2_3_intro, ex1_2_intro, or3_intro2, or3_intro1/
+lemma csx_inv_lref_drops (G) (L):
+ ∀i. ❪G,L❫ ⊢ ⬈*𝐒 #i →
+ ∨∨ ⇩*[Ⓕ,𝐔❨i❩] L ≘ ⋆
+ | ∃∃I,K. ⇩[i] L ≘ K.ⓤ[I]
+ | ∃∃I,K,V. ⇩[i] L ≘ K.ⓑ[I]V & ❪G,K❫ ⊢ ⬈*𝐒 V.
+#G #L #i #H elim (drops_F_uni L i) /2 width=1 by or3_intro0/
+* * /4 width=9 by csx_inv_lref_pair_drops, ex2_3_intro, ex1_2_intro, or3_intro2, or3_intro1/