qed.
lemma lcosx_drop_trans_lt: ∀h,g,G,L,d. G ⊢ ~⬊*[h, g, d] L →
- â\88\80I,K,V,i. â\87©[i] L ≡ K.ⓑ{I}V → i < d →
+ â\88\80I,K,V,i. â¬\87[i] L ≡ K.ⓑ{I}V → i < d →
G ⊢ ~⬊*[h, g, ⫰(d-i)] K ∧ G ⊢ ⬊*[h, g, V, ⫰(d-i)] K.
#h #g #G #L #d #H elim H -L -d
[ #d #J #K #V #i #H elim (drop_inv_atom1 … H) -H #H destruct